diff --git a/include/rtc.h b/include/rtc.h
new file mode 100644
index 0000000000..fcc1a38ea2
--- /dev/null
+++ b/include/rtc.h
@@ -0,0 +1,28 @@
+#ifndef POKEPLATINUM_RTC_H
+#define POKEPLATINUM_RTC_H
+
+
+#include <nitro/rtc.h>
+
+enum TimeOfDay {
+    TOD_MORNING = 0,
+    TOD_DAY = 1,
+    TOD_TWILIGHT = 2,
+    TOD_NIGHT = 3,
+    TOD_LATE_NIGHT = 4,
+};
+
+void InitRTC(void);
+void UpdateRTC(void);
+void GetCurrentDateTime(RTCDate * date, RTCTime * time);
+void GetCurrentTime(RTCTime * time);
+void GetCurrentDate(RTCDate * date);
+int GetSecondsSinceMidnight(void);
+s64 GetTimestamp(void);
+int DayNumberForDate(const RTCDate * date);
+BOOL IsNight(void);
+enum TimeOfDay GetTimeOfDay(void);
+enum TimeOfDay TimeOfDayForHour(int hour);
+s64 TimeElapsed(s64 since, s64 until);
+
+#endif // POKEPLATINUM_RTC_H
diff --git a/include/unk_0201378C.h b/include/unk_0201378C.h
deleted file mode 100644
index 8e0b9d5070..0000000000
--- a/include/unk_0201378C.h
+++ /dev/null
@@ -1,20 +0,0 @@
-#ifndef POKEPLATINUM_UNK_0201378C_H
-#define POKEPLATINUM_UNK_0201378C_H
-
-
-#include <nitro/rtc.h>
-
-void sub_0201378C(void);
-void sub_020137C4(void);
-void sub_0201384C(RTCDate * param0, RTCTime * param1);
-void sub_02013880(RTCTime * param0);
-void sub_020138A4(RTCDate * param0);
-int sub_020138C8(void);
-s64 sub_020138EC(void);
-int sub_02013900(const RTCDate * param0);
-BOOL sub_02013948(void);
-int sub_02013960(void);
-int sub_02013974(int param0);
-s64 sub_0201398C(s64 param0, s64 param1);
-
-#endif // POKEPLATINUM_UNK_0201378C_H
diff --git a/platinum.us/main.lsf b/platinum.us/main.lsf
index b00b762dfe..01ae2f2eff 100644
--- a/platinum.us/main.lsf
+++ b/platinum.us/main.lsf
@@ -50,7 +50,7 @@ Static main
 	Object main.nef.p/src_unk_02012480.c.o
 	Object main.nef.p/src_unk_02012744.c.o
 	Object main.nef.p/src_unk_020131EC.c.o
-	Object main.nef.p/src_unk_0201378C.c.o
+	Object main.nef.p/src_rtc.c.o
 	Object main.nef.p/src_unk_02013A04.c.o
 	Object main.nef.p/src_unk_02013B10.c.o
 	Object main.nef.p/src_unk_02014000.c.o
diff --git a/src/main.c b/src/main.c
index cd7aa3a202..fa2038fee7 100644
--- a/src/main.c
+++ b/src/main.c
@@ -20,7 +20,7 @@
 #include "unk_020067E8.h"
 #include "unk_0200A9DC.h"
 #include "unk_0200F174.h"
-#include "unk_0201378C.h"
+#include "rtc.h"
 #include "unk_02017428.h"
 #include "unk_02017728.h"
 #include "unk_0201CCF0.h"
@@ -75,7 +75,7 @@ void NitroMain (void)
     sub_02017B70(0);
     PM_GetBackLight(&sSavedBacklightState, NULL);
     sub_0202419C();
-    sub_0201378C();
+    InitRTC();
     sub_02000E3C();
     sub_02002B7C();
 
@@ -144,7 +144,7 @@ void NitroMain (void)
             }
         }
 
-        sub_020137C4();
+        UpdateRTC();
         sub_02017458();
         sub_020241CC();
         sub_0201CDD4(gCoreSys.unk_24);
@@ -323,7 +323,7 @@ void InitRNG (void)
     RTCTime v1;
     u32 v2;
 
-    sub_0201384C(&v0, &v1);
+    GetCurrentDateTime(&v0, &v1);
 
     v2 = v0.year + v0.month * 0x100 * v0.day * 0x10000 + v1.hour * 0x10000 + (v1.minute + v1.second) * 0x1000000 + gCoreSys.frameCounter;
 
diff --git a/src/meson.build b/src/meson.build
index a1f8afa532..948132a3f1 100644
--- a/src/meson.build
+++ b/src/meson.build
@@ -46,7 +46,7 @@ pokeplatinum_c = files(
     'unk_02012480.c',
     'unk_02012744.c',
     'unk_020131EC.c',
-    'unk_0201378C.c',
+    'rtc.c',
     'unk_02013A04.c',
     'unk_02013B10.c',
     'unk_02014000.c',
diff --git a/src/overlay005/ov5_021D521C.c b/src/overlay005/ov5_021D521C.c
index f8d82d5761..c110bf8e80 100644
--- a/src/overlay005/ov5_021D521C.c
+++ b/src/overlay005/ov5_021D521C.c
@@ -5,7 +5,7 @@
 #include "overlay005/struct_ov5_021D5894.h"
 
 #include "unk_02006E3C.h"
-#include "unk_0201378C.h"
+#include "rtc.h"
 #include "heap.h"
 #include "unk_0201E0A4.h"
 #include "overlay005/ov5_021D521C.h"
@@ -39,7 +39,7 @@ UnkStruct_ov5_021D538C * ov5_021D521C (UnkStruct_ov5_021D5894 * param0, const u8
     v1->unk_00 = ov5_021D53D4(param1, &v1->unk_04);
     v1->unk_08 = 0;
 
-    v2 = sub_020138C8() / 2;
+    v2 = GetSecondsSinceMidnight() / 2;
 
     for (v0 = 0; v0 < v1->unk_00; v0++) {
         if (v1->unk_04[v0].unk_00 > v2) {
@@ -74,7 +74,7 @@ void ov5_021D5298 (UnkStruct_ov5_021D538C * param0)
 
     GF_ASSERT(param0);
 
-    v4 = sub_020138C8() / 2;
+    v4 = GetSecondsSinceMidnight() / 2;
 
     if (param0->unk_00 > 1) {
         if ((param0->unk_08 - 1) >= 0) {
diff --git a/src/overlay005/ov5_021F134C.c b/src/overlay005/ov5_021F134C.c
index 7422454526..9042dff90f 100644
--- a/src/overlay005/ov5_021F134C.c
+++ b/src/overlay005/ov5_021F134C.c
@@ -12,7 +12,7 @@
 #include "overlay101/struct_ov101_021D86B0.h"
 
 #include "unk_0200D9E8.h"
-#include "unk_0201378C.h"
+#include "rtc.h"
 #include "unk_02061804.h"
 #include "unk_020711EC.h"
 #include "unk_02073838.h"
@@ -138,7 +138,7 @@ static void ov5_021F1424 (SysTask * param0, void * param1)
     int v0;
     UnkStruct_ov5_021F1388 * v1 = param1;
 
-    v0 = sub_02013960();
+    v0 = GetTimeOfDay();
 
     switch (v1->unk_00) {
     case 0:
diff --git a/src/overlay006/ov6_02240C9C.c b/src/overlay006/ov6_02240C9C.c
index 1cd0cace76..167a8789eb 100644
--- a/src/overlay006/ov6_02240C9C.c
+++ b/src/overlay006/ov6_02240C9C.c
@@ -17,7 +17,7 @@
 #include "overlay006/struct_ov6_02242634_sub2.h"
 
 #include "narc.h"
-#include "unk_0201378C.h"
+#include "rtc.h"
 #include "heap.h"
 #include "unk_0201D15C.h"
 #include "unk_02025E08.h"
@@ -175,7 +175,7 @@ void ov6_02240C9C (const UnkStruct_ov6_02242634 * param0, int * param1, int * pa
 {
     int v0;
 
-    v0 = sub_02013960();
+    v0 = GetTimeOfDay();
 
     if ((v0 == 1) || (v0 == 2)) {
         (*param1) = param0->unk_48[0];
diff --git a/src/overlay006/ov6_022465FC.c b/src/overlay006/ov6_022465FC.c
index aa9537bb68..89609432e8 100644
--- a/src/overlay006/ov6_022465FC.c
+++ b/src/overlay006/ov6_022465FC.c
@@ -8,7 +8,7 @@
 #include "struct_defs/struct_0203CDB0.h"
 
 #include "narc.h"
-#include "unk_0201378C.h"
+#include "rtc.h"
 #include "unk_0201D15C.h"
 #include "savedata/save_table.h"
 #include "unk_0202E2CC.h"
@@ -301,7 +301,7 @@ int ov6_02246978 (UnkStruct_0203CDB0 * param0, int param1)
     default:
         GF_ASSERT(0);
     case 0:
-        switch (sub_02013960()) {
+        switch (GetTimeOfDay()) {
         case 0:
             return v1->unk_00;
         case 1:
diff --git a/src/overlay006/ov6_02246B74.c b/src/overlay006/ov6_02246B74.c
index d063732933..3334ce3da2 100644
--- a/src/overlay006/ov6_02246B74.c
+++ b/src/overlay006/ov6_02246B74.c
@@ -1,7 +1,7 @@
 #include <nitro.h>
 #include <string.h>
 
-#include "unk_0201378C.h"
+#include "rtc.h"
 #include "overlay006/ov6_02246B74.h"
 
 typedef struct {
@@ -126,7 +126,7 @@ int ov6_02246B74 (const int param0, const BOOL param1)
         return 0;
     }
 
-    sub_020138A4(&v2);
+    GetCurrentDate(&v2);
 
     GF_ASSERT(v2.month > 0);
     GF_ASSERT(v2.month <= 12);
diff --git a/src/overlay026/ov26_022561C0.c b/src/overlay026/ov26_022561C0.c
index 800ad15b51..aaaebef433 100644
--- a/src/overlay026/ov26_022561C0.c
+++ b/src/overlay026/ov26_022561C0.c
@@ -12,7 +12,7 @@
 #include "overlay026/struct_ov26_02256404_1.h"
 
 #include "unk_0200D9E8.h"
-#include "unk_0201378C.h"
+#include "rtc.h"
 #include "heap.h"
 #include "overlay025/ov25_02253CE0.h"
 #include "overlay025/ov25_02255ACC.h"
@@ -85,7 +85,7 @@ static BOOL ov26_0225621C (UnkStruct_ov26_0225621C * param0, UnkStruct_ov25_0225
         param0->unk_07 = 0;
         param0->unk_14.unk_0C = 0;
 
-        sub_02013880(&(param0->unk_14.unk_00));
+        GetCurrentTime(&(param0->unk_14.unk_00));
 
         if (param0->unk_14.unk_00.hour >= 24) {
             param0->unk_14.unk_00.hour %= 24;
@@ -203,7 +203,7 @@ static BOOL ov26_02256370 (UnkStruct_ov26_0225621C * param0)
     if (ov26_022564CC(param0->unk_24, 1)) {
         param0->unk_06 = param0->unk_14.unk_00.minute;
         param0->unk_05 = param0->unk_14.unk_00.hour;
-        sub_02013880(&(param0->unk_14.unk_00));
+        GetCurrentTime(&(param0->unk_14.unk_00));
 
         if ((param0->unk_06 != param0->unk_14.unk_00.minute) || (param0->unk_05 != param0->unk_14.unk_00.hour)) {
             ov26_022564A8(param0->unk_24, 1);
diff --git a/src/overlay030/ov30_022561C0.c b/src/overlay030/ov30_022561C0.c
index 886ec8a1d1..2b60bd750f 100644
--- a/src/overlay030/ov30_022561C0.c
+++ b/src/overlay030/ov30_022561C0.c
@@ -12,7 +12,7 @@
 #include "overlay030/struct_ov30_022563EC_1.h"
 
 #include "unk_0200D9E8.h"
-#include "unk_0201378C.h"
+#include "rtc.h"
 #include "heap.h"
 #include "overlay025/ov25_02253CE0.h"
 #include "overlay025/ov25_02255ACC.h"
@@ -84,7 +84,7 @@ static BOOL ov30_0225621C (UnkStruct_ov30_0225621C * param0, UnkStruct_ov25_0225
         param0->unk_06 = 0;
         param0->unk_14.unk_0C = 0;
 
-        sub_02013880(&(param0->unk_14.unk_00));
+        GetCurrentTime(&(param0->unk_14.unk_00));
 
         if (param0->unk_14.unk_00.hour >= 24) {
             param0->unk_14.unk_00.hour %= 24;
@@ -201,7 +201,7 @@ static BOOL ov30_02256364 (UnkStruct_ov30_0225621C * param0)
 
     if (ov30_02256488(param0->unk_24, 1)) {
         param0->unk_05 = param0->unk_14.unk_00.minute;
-        sub_02013880(&(param0->unk_14.unk_00));
+        GetCurrentTime(&(param0->unk_14.unk_00));
 
         if (param0->unk_05 != param0->unk_14.unk_00.minute) {
             ov30_02256464(param0->unk_24, 1);
diff --git a/src/overlay045/ov45_022561C0.c b/src/overlay045/ov45_022561C0.c
index a58785a8fe..2e13d3fe68 100644
--- a/src/overlay045/ov45_022561C0.c
+++ b/src/overlay045/ov45_022561C0.c
@@ -13,7 +13,7 @@
 #include "overlay045/struct_ov45_022566EC_1.h"
 
 #include "unk_0200D9E8.h"
-#include "unk_0201378C.h"
+#include "rtc.h"
 #include "heap.h"
 #include "unk_02056720.h"
 #include "overlay025/ov25_02253CE0.h"
@@ -127,7 +127,7 @@ static void ov45_022562C0 (UnkStruct_ov45_022566EC_1 * param0)
 {
     RTCTime v0;
 
-    sub_02013880(&v0);
+    GetCurrentTime(&v0);
 
     if (v0.hour >= 24) {
         v0.hour %= 24;
@@ -398,7 +398,7 @@ static BOOL ov45_02256664 (UnkStruct_ov45_022561D4 * param0)
 static void ov45_02256668 (UnkStruct_ov45_022561D4 * param0)
 {
     if (param0->unk_2C == 0) {
-        sub_02013880(&(param0->unk_20));
+        GetCurrentTime(&(param0->unk_20));
         param0->unk_30 = 1;
     }
 }
diff --git a/src/overlay050/ov50_022561C0.c b/src/overlay050/ov50_022561C0.c
index 876b629f69..1ef5f661b9 100644
--- a/src/overlay050/ov50_022561C0.c
+++ b/src/overlay050/ov50_022561C0.c
@@ -13,7 +13,7 @@
 #include "overlay050/struct_ov50_02256510_1.h"
 
 #include "unk_0200D9E8.h"
-#include "unk_0201378C.h"
+#include "rtc.h"
 #include "heap.h"
 #include "unk_02056720.h"
 #include "overlay025/ov25_02253CE0.h"
@@ -115,7 +115,7 @@ static BOOL ov50_0225621C (UnkStruct_ov50_022561D4 * param0, UnkStruct_ov25_0225
     };
     RTCDate v1;
 
-    sub_020138A4(&v1);
+    GetCurrentDate(&v1);
     param0->unk_98 = ov25_02254540(param1);
     ov50_022562AC(&(param0->unk_04), param0, &v1);
 
diff --git a/src/overlay065/ov65_0222DCE0.c b/src/overlay065/ov65_0222DCE0.c
index cb2f51611d..a47f298111 100644
--- a/src/overlay065/ov65_0222DCE0.c
+++ b/src/overlay065/ov65_0222DCE0.c
@@ -64,7 +64,7 @@
 #include "unk_0200DA60.h"
 #include "unk_0200F174.h"
 #include "unk_02012744.h"
-#include "unk_0201378C.h"
+#include "rtc.h"
 #include "unk_02013A04.h"
 #include "unk_02017728.h"
 #include "heap.h"
@@ -3822,7 +3822,7 @@ static void ov65_02231A0C (void)
     ov4_021D2584(0);
 
     if (ov65_02231A54() == 0) {
-        if (sub_02013948() == 0) {
+        if (IsNight() == 0) {
             v0 = 1085;
         } else {
             v0 = 1086;
diff --git a/src/overlay067/ov67_0225C700.c b/src/overlay067/ov67_0225C700.c
index a14835e228..d12e8ed92e 100644
--- a/src/overlay067/ov67_0225C700.c
+++ b/src/overlay067/ov67_0225C700.c
@@ -36,7 +36,7 @@
 #include "unk_0200B358.h"
 #include "unk_0200DA60.h"
 #include "unk_0200F174.h"
-#include "unk_0201378C.h"
+#include "rtc.h"
 #include "unk_02017728.h"
 #include "heap.h"
 #include "unk_02018340.h"
@@ -286,7 +286,7 @@ int ov67_0225C820 (UnkStruct_020067E8 * param0, int * param1)
             }
 
             {
-                v1->unk_0C->unk_00 = sub_020138EC();
+                v1->unk_0C->unk_00 = GetTimestamp();
             }
 
             v1->unk_10 = 1;
diff --git a/src/overlay077/ov77_021D6C70.c b/src/overlay077/ov77_021D6C70.c
index 3660536c94..3219d035b6 100644
--- a/src/overlay077/ov77_021D6C70.c
+++ b/src/overlay077/ov77_021D6C70.c
@@ -11,7 +11,7 @@
 #include "spl.h"
 
 #include "unk_0200762C.h"
-#include "unk_0201378C.h"
+#include "rtc.h"
 #include "unk_02014000.h"
 #include "heap.h"
 #include "unk_02020020.h"
@@ -120,7 +120,7 @@ void ov77_021D6CFC (UnkStruct_ov77_021D6CFC * param0)
     int v6, v7;
     RTCTime v8;
 
-    sub_02013880(&v8);
+    GetCurrentTime(&v8);
 
     v6 = (v8.hour * v8.minute + v8.second) & 1;
     v7 = v8.second % 3;
diff --git a/src/overlay088/ov88_0223B140.c b/src/overlay088/ov88_0223B140.c
index 9c9d07cae6..e1c08eeaf0 100644
--- a/src/overlay088/ov88_0223B140.c
+++ b/src/overlay088/ov88_0223B140.c
@@ -59,7 +59,7 @@
 #include "unk_0200DA60.h"
 #include "unk_0200F174.h"
 #include "unk_020131EC.h"
-#include "unk_0201378C.h"
+#include "rtc.h"
 #include "unk_02013A04.h"
 #include "unk_02017728.h"
 #include "heap.h"
@@ -336,7 +336,7 @@ int ov88_0223B140 (UnkStruct_020067E8 * param0, int * param1)
     sub_02038A1C(26, v0->unk_174);
     sub_02039734();
 
-    if (sub_02013948() == 0) {
+    if (IsNight() == 0) {
         sub_02004550(4, 1085, 1);
         sub_02004A84(1085);
     } else {
diff --git a/src/overlay097/ov97_0222C174.c b/src/overlay097/ov97_0222C174.c
index f7d67a27fd..90587c7f48 100644
--- a/src/overlay097/ov97_0222C174.c
+++ b/src/overlay097/ov97_0222C174.c
@@ -40,7 +40,7 @@
 #include "unk_0200B29C.h"
 #include "unk_0200B358.h"
 #include "unk_0200DA60.h"
-#include "unk_0201378C.h"
+#include "rtc.h"
 #include "heap.h"
 #include "unk_02018340.h"
 #include "unk_0201D670.h"
@@ -840,7 +840,7 @@ static void ov97_0222C974 (UnkStruct_ov97_0222C388 * param0)
     v4->unk_34A[1] = 0;
     v4->unk_34A[2] = 0;
     v4->unk_350 = 0;
-    sub_020138A4(&v0);
+    GetCurrentDate(&v0);
     v4->unk_354 = RTC_ConvertDateToDay(&v0);
 
     sub_0200B3F0(v2);
diff --git a/src/overlay097/ov97_0222D30C.c b/src/overlay097/ov97_0222D30C.c
index 31dc13aeaf..9f8ecddb48 100644
--- a/src/overlay097/ov97_0222D30C.c
+++ b/src/overlay097/ov97_0222D30C.c
@@ -50,7 +50,7 @@
 #include "unk_0200D9E8.h"
 #include "unk_0200DA60.h"
 #include "unk_0200F174.h"
-#include "unk_0201378C.h"
+#include "rtc.h"
 #include "unk_02013A04.h"
 #include "unk_02017728.h"
 #include "heap.h"
@@ -460,7 +460,7 @@ static void ov97_0222D658 (UnkStruct_020067E8 * param0)
             v4->val2.unk_348 = 0;
         }
 
-        sub_020138A4(&v7);
+        GetCurrentDate(&v7);
         v4->val2.unk_354 = RTC_ConvertDateToDay(&v7);
     }
 
diff --git a/src/pokemon.c b/src/pokemon.c
index 736dec94f7..d69eb70705 100644
--- a/src/pokemon.c
+++ b/src/pokemon.c
@@ -31,7 +31,7 @@
 #include "message.h"
 #include "unk_0200B29C.h"
 #include "unk_0200C6E4.h"
-#include "unk_0201378C.h"
+#include "rtc.h"
 #include "unk_02015F84.h"
 #include "unk_02017038.h"
 #include "heap.h"
@@ -3136,13 +3136,13 @@ u16 sub_02076B94(Party *party, Pokemon *mon, u8 evoTypeList, u16 evoParam, int *
                 }
                 break;
             case 2:  // high friendship && daytime
-                if (sub_02013948() == 0 && 220 <= monFriendship) {
+                if (IsNight() == 0 && 220 <= monFriendship) {
                     targetSpecies = monEvolutionData->methods[i].targetSpecies;
                     evoTypeResult[0] = 2;
                 }
                 break;
             case 3:  // high friendship && nighttime
-                if (sub_02013948() == 1 && 220 <= monFriendship) {
+                if (IsNight() == 1 && 220 <= monFriendship) {
                     targetSpecies = monEvolutionData->methods[i].targetSpecies;
                     evoTypeResult[0] = 3;
                 }
@@ -3209,13 +3209,13 @@ u16 sub_02076B94(Party *party, Pokemon *mon, u8 evoTypeList, u16 evoParam, int *
                 }
                 break;
             case 18:  // happiny evo: hold param && daytime
-                if (sub_02013948() == 0 && monEvolutionData->methods[i].param == monHeldItem) {
+                if (IsNight() == 0 && monEvolutionData->methods[i].param == monHeldItem) {
                     targetSpecies = monEvolutionData->methods[i].targetSpecies;
                     evoTypeResult[0] = 18;
                 }
                 break;
             case 19:  // sneasel and gligar evo: hold param && nighttime
-                if (sub_02013948() == 1 && monEvolutionData->methods[i].param == monHeldItem) {
+                if (IsNight() == 1 && monEvolutionData->methods[i].param == monHeldItem) {
                     targetSpecies = monEvolutionData->methods[i].targetSpecies;
                     evoTypeResult[0] = 19;
                 }
@@ -4033,7 +4033,7 @@ BOOL Pokemon_CanShayminSkyForm(Pokemon *mon)
     u32 monFatefulEncounter = Pokemon_GetValue(mon, MON_DATA_FATEFUL_ENCOUNTER, NULL);
 
     RTCTime rtcTime;
-    sub_02013880(&rtcTime);
+    GetCurrentTime(&rtcTime);
 
     return (monSpecies == SPECIES_SHAYMIN
             && monForm == 0
diff --git a/src/rtc.c b/src/rtc.c
new file mode 100644
index 0000000000..6b40d23997
--- /dev/null
+++ b/src/rtc.c
@@ -0,0 +1,192 @@
+#include <nitro.h>
+#include <string.h>
+#include <nnsys.h>
+
+#include "inlines.h"
+
+#include "rtc.h"
+
+typedef struct {
+    BOOL valid;
+    BOOL readInProgress;
+    int framesSinceRead;
+    RTCResult status;
+    RTCDate date;
+    RTCTime time;
+    RTCDate tempDate;
+    RTCTime tempTime;
+} RTCState;
+
+static void GetTimeCallback(RTCResult param0, void * param1);
+static void StartRTCRead(RTCState * param0);
+
+static RTCState sRTCState;
+
+void InitRTC (void)
+{
+    RTC_Init();
+    memset(&sRTCState, 0, sizeof(sRTCState));
+    sRTCState.valid = 0;
+    sRTCState.readInProgress = 0;
+    sRTCState.framesSinceRead = 0;
+    StartRTCRead(&sRTCState);
+}
+
+void UpdateRTC (void)
+{
+    if (sRTCState.readInProgress) {
+        return;
+    }
+
+    sRTCState.framesSinceRead++;
+
+    if (sRTCState.framesSinceRead > 10) {
+        sRTCState.framesSinceRead = 0;
+        StartRTCRead(&sRTCState);
+    }
+}
+
+static void GetTimeCallback (RTCResult result, void * data)
+{
+    RTCState * state = data;
+
+    state->status = result;
+
+    GF_ASSERT(result == RTC_RESULT_SUCCESS);
+
+    state->valid = 1;
+    state->date = state->tempDate;
+    state->time = state->tempTime;
+    state->readInProgress = 0;
+}
+
+static void StartRTCRead (RTCState * param0)
+{
+    param0->readInProgress = 1;
+    param0->status = RTC_GetDateTimeAsync(&param0->tempDate, &param0->tempTime, GetTimeCallback, param0);
+    GF_ASSERT(param0->status == RTC_RESULT_SUCCESS);
+}
+
+void GetCurrentDateTime (RTCDate * date, RTCTime * time)
+{
+    GF_ASSERT(sRTCState.valid == 1);
+
+    *date = sRTCState.date;
+    *time = sRTCState.time;
+}
+
+void GetCurrentTime (RTCTime * time)
+{
+    GF_ASSERT(sRTCState.valid == 1);
+    *time = sRTCState.time;
+}
+
+void GetCurrentDate (RTCDate * date)
+{
+    GF_ASSERT(sRTCState.valid == 1);
+    *date = sRTCState.date;
+}
+
+int GetSecondsSinceMidnight (void)
+{
+    RTCTime * time = &sRTCState.time;
+
+    return time->hour * 60 * 60 + time->minute * 60 + time->second;
+}
+
+s64 GetTimestamp (void)
+{
+    return RTC_ConvertDateTimeToSecond(&sRTCState.date, &sRTCState.time);
+}
+
+int DayNumberForDate (const RTCDate * date)
+{
+    int year, days;
+    static const u16 monthStart[12] = {
+        0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334
+    };
+
+    days = date->day;
+    days += monthStart[date->month - 1];
+
+    if (date->month >= 3) {
+        year = date->year;
+
+        if (((year % 4 == 0) && (year % 100 != 0)) || (year % 400 == 0)) {
+            days++;
+        }
+    }
+
+    return days;
+}
+
+BOOL IsNight (void)
+{
+    switch (GetTimeOfDay()) {
+    case TOD_LATE_NIGHT:
+    case TOD_NIGHT:
+        return 1;
+    }
+
+    return 0;
+}
+
+enum TimeOfDay GetTimeOfDay (void)
+{
+    RTCTime time;
+
+    GetCurrentTime(&time);
+    return TimeOfDayForHour(time.hour);
+}
+
+enum TimeOfDay TimeOfDayForHour (int hour)
+{
+    static const u8 lookup[24] = {
+        TOD_LATE_NIGHT,
+        TOD_LATE_NIGHT,
+        TOD_LATE_NIGHT,
+        TOD_LATE_NIGHT,
+        TOD_MORNING,
+        TOD_MORNING,
+        TOD_MORNING,
+        TOD_MORNING,
+        TOD_MORNING,
+        TOD_MORNING,
+        TOD_DAY,
+        TOD_DAY,
+        TOD_DAY,
+        TOD_DAY,
+        TOD_DAY,
+        TOD_DAY,
+        TOD_DAY,
+        TOD_TWILIGHT,
+        TOD_TWILIGHT,
+        TOD_TWILIGHT,
+        TOD_NIGHT,
+        TOD_NIGHT,
+        TOD_NIGHT,
+        TOD_NIGHT,
+    };
+
+    GF_ASSERT(0 <= hour && hour < 24);
+    return lookup[hour];
+}
+
+#define MAX_TIMESTAMP 3155759999
+
+s64 TimeElapsed (s64 since, s64 until)
+{
+    RTCDate maxDate = {99, 12, 31, 0};
+    RTCTime maxTime = {23, 59, 59};
+    s64 maxTimestamp = RTC_ConvertDateTimeToSecond(&maxDate, &maxTime);
+
+    GF_ASSERT(maxTimestamp == MAX_TIMESTAMP);
+
+    if (since < until) {
+        return until - since;
+    } else {
+        // BUG: This loses one second when rolling over.
+        // e.g. TimeElapsed(MAX_TIMESTAMP, 0) == 0
+        return until + (MAX_TIMESTAMP - since);
+    }
+}
diff --git a/src/unk_0201378C.c b/src/unk_0201378C.c
deleted file mode 100644
index a6f9bf90a6..0000000000
--- a/src/unk_0201378C.c
+++ /dev/null
@@ -1,212 +0,0 @@
-#include <nitro.h>
-#include <string.h>
-#include <nnsys.h>
-
-#include "inlines.h"
-
-#include "unk_0201378C.h"
-
-typedef struct {
-    BOOL unk_00;
-    BOOL unk_04;
-    int unk_08;
-    RTCResult unk_0C;
-    RTCDate unk_10;
-    RTCTime unk_20;
-    RTCDate unk_2C;
-    RTCTime unk_3C;
-} UnkStruct_021BF5C8;
-
-static void sub_020137EC(RTCResult param0, void * param1);
-static void sub_02013824(UnkStruct_021BF5C8 * param0);
-
-static UnkStruct_021BF5C8 Unk_021BF5C8;
-
-void sub_0201378C (void)
-{
-    RTC_Init();
-    memset(&Unk_021BF5C8, 0, sizeof(Unk_021BF5C8));
-    Unk_021BF5C8.unk_00 = 0;
-    Unk_021BF5C8.unk_04 = 0;
-    Unk_021BF5C8.unk_08 = 0;
-    sub_02013824(&Unk_021BF5C8);
-}
-
-void sub_020137C4 (void)
-{
-    RTCResult v0;
-
-    if (Unk_021BF5C8.unk_04) {
-        return;
-    }
-
-    Unk_021BF5C8.unk_08++;
-
-    if (Unk_021BF5C8.unk_08 > 10) {
-        Unk_021BF5C8.unk_08 = 0;
-        sub_02013824(&Unk_021BF5C8);
-    }
-}
-
-static void sub_020137EC (RTCResult param0, void * param1)
-{
-    UnkStruct_021BF5C8 * v0 = param1;
-
-    v0->unk_0C = param0;
-
-    GF_ASSERT(param0 == RTC_RESULT_SUCCESS);
-
-    v0->unk_00 = 1;
-    v0->unk_10 = v0->unk_2C;
-    v0->unk_20 = v0->unk_3C;
-    v0->unk_04 = 0;
-}
-
-static void sub_02013824 (UnkStruct_021BF5C8 * param0)
-{
-    param0->unk_04 = 1;
-    param0->unk_0C = RTC_GetDateTimeAsync(&param0->unk_2C, &param0->unk_3C, sub_020137EC, param0);
-    GF_ASSERT(param0->unk_0C == RTC_RESULT_SUCCESS);
-}
-
-static inline RTCDate * inline_0201384C (UnkStruct_021BF5C8 * param0)
-{
-    return &param0->unk_10;
-}
-
-static inline RTCTime * inline_02013880 (UnkStruct_021BF5C8 * param0)
-{
-    return &param0->unk_20;
-}
-
-void sub_0201384C (RTCDate * param0, RTCTime * param1)
-{
-    GF_ASSERT(Unk_021BF5C8.unk_00 == 1);
-
-    *param0 = *inline_0201384C(&Unk_021BF5C8);
-    *param1 = *inline_02013880(&Unk_021BF5C8);
-}
-
-void sub_02013880 (RTCTime * param0)
-{
-    GF_ASSERT(Unk_021BF5C8.unk_00 == 1);
-    *param0 = *inline_02013880(&Unk_021BF5C8);
-}
-
-void sub_020138A4 (RTCDate * param0)
-{
-    GF_ASSERT(Unk_021BF5C8.unk_00 == 1);
-    *param0 = *inline_0201384C(&Unk_021BF5C8);
-}
-
-int sub_020138C8 (void)
-{
-    RTCTime * v0;
-
-    v0 = inline_02013880(&Unk_021BF5C8);
-    return v0->hour * 60 * 60 + v0->minute * 60 + v0->second;
-}
-
-s64 sub_020138EC (void)
-{
-    return RTC_ConvertDateTimeToSecond(inline_0201384C(&Unk_021BF5C8), inline_02013880(&Unk_021BF5C8));
-}
-
-int sub_02013900 (const RTCDate * param0)
-{
-    int v0, v1, v2;
-    static const u16 v3[12] = {
-        0x0,
-        0x1F,
-        0x3B,
-        0x5A,
-        0x78,
-        0x97,
-        0xB5,
-        0xD4,
-        0xF3,
-        0x111,
-        0x130,
-        0x14E
-    };
-
-    v1 = param0->day;
-    v1 += v3[param0->month - 1];
-
-    if (param0->month >= 3) {
-        v0 = param0->year;
-
-        if (((v0 % 4 == 0) && (v0 % 100 != 0)) || (v0 % 400 == 0)) {
-            v1++;
-        }
-    }
-
-    return v1;
-}
-
-BOOL sub_02013948 (void)
-{
-    switch (sub_02013960()) {
-    case 4:
-    case 3:
-        return 1;
-    }
-
-    return 0;
-}
-
-int sub_02013960 (void)
-{
-    RTCTime v0;
-
-    sub_02013880(&v0);
-    return sub_02013974(v0.hour);
-}
-
-int sub_02013974 (int param0)
-{
-    static const u8 v0[24] = {
-        0x4,
-        0x4,
-        0x4,
-        0x4,
-        0x0,
-        0x0,
-        0x0,
-        0x0,
-        0x0,
-        0x0,
-        0x1,
-        0x1,
-        0x1,
-        0x1,
-        0x1,
-        0x1,
-        0x1,
-        0x2,
-        0x2,
-        0x2,
-        0x3,
-        0x3,
-        0x3,
-        0x3
-    };
-
-    GF_ASSERT(0 <= param0 && param0 < 24);
-    return v0[param0];
-}
-
-s64 sub_0201398C (s64 param0, s64 param1)
-{
-    RTCDate v0 = {99, 12, 31, 0};
-    RTCTime v1 = {23, 59, 59};
-    s64 v2 = RTC_ConvertDateTimeToSecond(&v0, &v1);
-
-    GF_ASSERT(v2 == 3155759999);
-
-    if (param0 < param1) {
-        return param1 - param0;
-    }
-
-    return param1 + (3155759999 - param0);
-}
diff --git a/src/unk_02025CB0.c b/src/unk_02025CB0.c
index 8d472f3ca4..38e313373d 100644
--- a/src/unk_02025CB0.c
+++ b/src/unk_02025CB0.c
@@ -4,7 +4,7 @@
 #include "struct_decls/struct_021C0794_decl.h"
 #include "struct_defs/struct_02055BA8.h"
 
-#include "unk_0201378C.h"
+#include "rtc.h"
 #include "unk_020244AC.h"
 #include "unk_02025CB0.h"
 
@@ -113,7 +113,7 @@ void sub_02025D78 (UnkStruct_02025CCC * param0, s32 param1)
 void sub_02025D84 (UnkStruct_02055BA8 * param0)
 {
     param0->unk_00 = 1;
-    sub_0201384C(&param0->unk_04, &param0->unk_14);
+    GetCurrentDateTime(&param0->unk_04, &param0->unk_14);
     param0->unk_20 = RTC_ConvertDateToDay(&param0->unk_04);
     param0->unk_24 = RTC_ConvertDateTimeToSecond(&param0->unk_04, &param0->unk_14);
     param0->unk_2C = 0;
@@ -145,6 +145,6 @@ void sub_02025DC8 (UnkStruct_02055BA8 * param0, int param1)
 void sub_02025DE8 (UnkStruct_02055BA8 * param0)
 {
     param0->unk_34 = 60 * 24;
-    sub_0201384C(&param0->unk_04, &param0->unk_14);
+    GetCurrentDateTime(&param0->unk_04, &param0->unk_14);
     param0->unk_20 = RTC_ConvertDateToDay(&param0->unk_04);
 }
diff --git a/src/unk_0202854C.c b/src/unk_0202854C.c
index 49694d7d03..818f42eb62 100644
--- a/src/unk_0202854C.c
+++ b/src/unk_0202854C.c
@@ -12,7 +12,7 @@
 #include "struct_defs/struct_02029894_sub2.h"
 #include "struct_defs/struct_020298B0.h"
 
-#include "unk_0201378C.h"
+#include "rtc.h"
 #include "heap.h"
 #include "unk_0201D15C.h"
 #include "unk_020244AC.h"
@@ -103,7 +103,7 @@ void Underground_Init (UnkStruct_020298B0 * param0)
     RTCDate v1;
     RTCTime v2;
 
-    sub_0201384C(&v1, &v2);
+    GetCurrentDateTime(&v1, &v2);
     v0 = (((((((u32)v1.year * 32ULL + v1.month) * 32ULL) + v1.day) * 32ULL + v2.hour) * 32ULL + v2.minute) * 32ULL + (v2.second + gCoreSys.frameCounter));
 
     MI_CpuFill8(param0, 0, sizeof(UnkStruct_020298B0));
diff --git a/src/unk_0202ACE0.c b/src/unk_0202ACE0.c
index 65e81eae0a..a7554f3029 100644
--- a/src/unk_0202ACE0.c
+++ b/src/unk_0202ACE0.c
@@ -10,7 +10,7 @@
 #include "struct_defs/struct_0202B370.h"
 #include "struct_defs/struct_0202B370_sub1.h"
 
-#include "unk_0201378C.h"
+#include "rtc.h"
 #include "strbuf.h"
 #include "unk_020244AC.h"
 #include "unk_0202ACE0.h"
@@ -251,7 +251,7 @@ void sub_0202B13C (UnkStruct_0202B370 * param0, int param1)
 {
     RTCDate v0;
 
-    sub_020138A4(&v0);
+    GetCurrentDate(&v0);
 
     param0->unk_1C0[param1].unk_2A = v0.year + 2000;
     param0->unk_1C0[param1].unk_2C = v0.month;
diff --git a/src/unk_0202B604.c b/src/unk_0202B604.c
index c4ee52a541..0494274dc2 100644
--- a/src/unk_0202B604.c
+++ b/src/unk_0202B604.c
@@ -11,7 +11,7 @@
 #include "struct_defs/struct_0202BF4C.h"
 #include "struct_defs/struct_0202BFCC.h"
 
-#include "unk_0201378C.h"
+#include "rtc.h"
 #include "heap.h"
 #include "unk_020244AC.h"
 #include "trainer_info.h"
@@ -146,7 +146,7 @@ UnkStruct_0202B628 * sub_0202B634 (UnkStruct_0202B628 * param0, BOOL param1)
         return NULL;
     }
 
-    sub_020138A4(&v0);
+    GetCurrentDate(&v0);
 
     if ((param0[0].unk_00.unk_00_7 != 0) && ((param0[0].unk_00.unk_00_0 != v0.year) || (param0[0].unk_00.unk_00_7 != v0.month) || (param0[0].unk_00.unk_00_14 != v0.day) || (param0[0].unk_00.unk_00_11 != v0.week))) {
         for (v1 = 10 - 1; v1 >= 1; v1--) {
@@ -169,14 +169,14 @@ BOOL sub_0202B6A4 (UnkStruct_0202B628 * param0, BOOL param1)
         return 0;
     }
 
-    sub_020138A4(&v1);
+    GetCurrentDate(&v1);
 
     v0.year = param0[0].unk_00.unk_00_0;
     v0.month = param0[0].unk_00.unk_00_7;
     v0.day = param0[0].unk_00.unk_00_14;
     v0.week = param0[0].unk_00.unk_00_11;
 
-    v2 = sub_02013900(&v1) - sub_02013900(&v0);
+    v2 = DayNumberForDate(&v1) - DayNumberForDate(&v0);
 
     if (((v1.month == 12) && (v1.day == 31) && (v0.month == 1) && (v0.day == 1)) || ((v1.month == 1) && (v1.day == 1) && (v0.month == 12) && (v0.day == 31))) {
         s32 v3 = (s32)v1.year - (s32)v0.year;
@@ -580,7 +580,7 @@ void * sub_0202BC58 (u16 param0, u32 param1)
     RTCDate v1;
 
     v0 = Heap_AllocFromHeap(param1, sizeof(UnkStruct_0202BC58));
-    sub_020138A4(&v1);
+    GetCurrentDate(&v1);
 
     v0->unk_00_0 = v1.year;
     v0->unk_00_7 = v1.month;
diff --git a/src/unk_0202E2CC.c b/src/unk_0202E2CC.c
index 527c546b2b..b70e1c14cf 100644
--- a/src/unk_0202E2CC.c
+++ b/src/unk_0202E2CC.c
@@ -17,7 +17,7 @@
 #include "struct_defs/struct_0202E828.h"
 #include "struct_defs/struct_0202E834.h"
 
-#include "unk_0201378C.h"
+#include "rtc.h"
 #include "unk_020244AC.h"
 #include "unk_0202E2CC.h"
 
@@ -144,7 +144,7 @@ static void sub_0202E3F4 (UnkStruct_0202E4D4 * param0, int param1, const u8 * pa
 {
     RTCDate v0;
 
-    sub_020138A4(&v0);
+    GetCurrentDate(&v0);
 
     param0->unk_04 = inline_0202D4B0(&v0);
     param0->unk_00 = param1;
diff --git a/src/unk_0202EEC0.c b/src/unk_0202EEC0.c
index 7301143ba3..253ebf3826 100644
--- a/src/unk_0202EEC0.c
+++ b/src/unk_0202EEC0.c
@@ -3,7 +3,7 @@
 
 #include "pokemon.h"
 
-#include "unk_0201378C.h"
+#include "rtc.h"
 #include "unk_0202EEC0.h"
 #include "pokemon.h"
 
@@ -83,7 +83,7 @@ void sub_0202EFB8 (PalParkTransfer * param0, u32 param1)
     int v0 = sub_0202EF40(param0, param1);
 
     param0->unk_288[v0] = param1;
-    param0->unk_2D8[v0] = sub_020138EC();
+    param0->unk_2D8[v0] = GetTimestamp();
     param0->unk_378 = OS_GetOwnerRtcOffset();
 
     OS_GetMacAddress(param0->unk_380);
@@ -111,7 +111,7 @@ int sub_0202F028 (const PalParkTransfer * param0)
 int sub_0202F050 (const PalParkTransfer * param0, u32 param1)
 {
     int v0;
-    s64 v1 = sub_020138EC();
+    s64 v1 = GetTimestamp();
 
     for (v0 = 0; v0 < 20; v0++) {
         if (param0->unk_288[v0] == param1) {
diff --git a/src/unk_02034198.c b/src/unk_02034198.c
index 7ac0bd5e39..8650988c3f 100644
--- a/src/unk_02034198.c
+++ b/src/unk_02034198.c
@@ -12,7 +12,7 @@
 #include "struct_defs/struct_0203233C.h"
 
 #include "unk_0200D9E8.h"
-#include "unk_0201378C.h"
+#include "rtc.h"
 #include "heap.h"
 #include "unk_02030EE0.h"
 #include "unk_02032188.h"
@@ -1876,7 +1876,7 @@ void sub_020361BC (MATHRandContext32 * param0)
     RTCDate v1;
     RTCTime v2;
 
-    sub_0201384C(&v1, &v2);
+    GetCurrentDateTime(&v1, &v2);
     v0 = (((((((u64)v1.year * 16ULL + v1.month) * 32ULL) + v1.day) * 32ULL + v2.hour) * 64ULL + v2.minute) * 64ULL + (v2.second + gCoreSys.frameCounter));
     MATH_InitRand32(param0, v0);
 }
diff --git a/src/unk_0203A944.c b/src/unk_0203A944.c
index 784e96024d..6b339dc7df 100644
--- a/src/unk_0203A944.c
+++ b/src/unk_0203A944.c
@@ -6,7 +6,7 @@
 #include "struct_defs/struct_0203CDB0.h"
 #include "struct_defs/struct_02055BA8.h"
 
-#include "unk_0201378C.h"
+#include "rtc.h"
 #include "unk_02025CB0.h"
 #include "map_header.h"
 #include "unk_0203A944.h"
@@ -1860,7 +1860,7 @@ int sub_0203A944 (UnkStruct_0203CDB0 * param0, int param1)
         int v1;
         UnkStruct_02055BA8 * v2 = sub_02025CD8(param0->unk_0C);
 
-        v1 = sub_02013900(&v2->unk_04) - 1;
+        v1 = DayNumberForDate(&v2->unk_04) - 1;
         GF_ASSERT(v1 >= 0 && v1 < 366);
 
         if ((v2->unk_04.month > 2) && !inline_0203A944(v2->unk_04.year)) {
diff --git a/src/unk_0203D1B8.c b/src/unk_0203D1B8.c
index f98e101fbf..83dff3b133 100644
--- a/src/unk_0203D1B8.c
+++ b/src/unk_0203D1B8.c
@@ -67,7 +67,7 @@
 #include "overlay088/struct_ov88_0223C370.h"
 #include "overlay090/struct_ov90_021D0D80.h"
 
-#include "unk_0201378C.h"
+#include "rtc.h"
 #include "unk_02017498.h"
 #include "heap.h"
 #include "unk_0201D15C.h"
@@ -1594,9 +1594,9 @@ static BOOL sub_0203E35C (UnkStruct_020508D4 * param0)
     case 1:
         if (sub_020509B4(v0) == 0) {
             u16 * v5 = sub_02025E50(v0->unk_0C);
-            s64 v6 = sub_020138EC();
+            s64 v6 = GetTimestamp();
 
-            sub_0206DD38(v0, Coins_GetValue(v5), v2->unk_00, sub_0201398C(v2->unk_04, v6) / 60);
+            sub_0206DD38(v0, Coins_GetValue(v5), v2->unk_00, TimeElapsed(v2->unk_04, v6) / 60);
             Coins_SetValue(sub_02025E50(v0->unk_0C), v2->unk_00);
 
             v4 = sub_0206B394(v1);
@@ -1622,7 +1622,7 @@ void sub_0203E414 (UnkStruct_020508D4 * param0, int param1)
 
     v2->unk_0C.unk_00 = &v2->unk_00;
     v2->unk_00 = Coins_GetValue(sub_02025E50(v0->unk_0C));
-    v2->unk_04 = sub_020138EC();
+    v2->unk_04 = GetTimestamp();
     v2->unk_0C.unk_08 = sub_0202CD88(v0->unk_0C);
     v2->unk_0C.unk_0C = 0;
     v2->unk_0C.unk_10 = sub_02027B50(v1);
diff --git a/src/unk_0203F6C4.c b/src/unk_0203F6C4.c
index e963bd8616..59691300b8 100644
--- a/src/unk_0203F6C4.c
+++ b/src/unk_0203F6C4.c
@@ -77,7 +77,7 @@
 #include "unk_0200D9E8.h"
 #include "unk_0200DA60.h"
 #include "unk_0200F174.h"
-#include "unk_0201378C.h"
+#include "rtc.h"
 #include "unk_02014D38.h"
 #include "heap.h"
 #include "unk_02018340.h"
@@ -6750,7 +6750,7 @@ static BOOL sub_02044EDC (UnkStruct_0203E724 * param0)
     RTCDate v0;
     u16 * v1 = inline_0204FCAC(param0);
 
-    sub_020138A4(&v0);
+    GetCurrentDate(&v0);
     *v1 = v0.week;
 
     return 0;
@@ -8435,7 +8435,7 @@ static BOOL sub_0204698C (UnkStruct_0203E724 * param0)
     s64 v2;
     s64 v3;
 
-    v2 = sub_020138EC();
+    v2 = GetTimestamp();
     v3 = v2 - v0->unk_C4.unk_00;
 
     if (v3 >= 120) {
diff --git a/src/unk_02051D8C.c b/src/unk_02051D8C.c
index dd84a001b5..2ddec6b85d 100644
--- a/src/unk_02051D8C.c
+++ b/src/unk_02051D8C.c
@@ -28,7 +28,7 @@
 
 #include "unk_020021B0.h"
 #include "message.h"
-#include "unk_0201378C.h"
+#include "rtc.h"
 #include "heap.h"
 #include "strbuf.h"
 #include "savedata/save_table.h"
@@ -119,7 +119,7 @@ BattleParams * sub_02051D8C (int param0, u32 param1)
         RTCDate v2;
         RTCTime v3;
 
-        sub_0201384C(&v2, &v3);
+        GetCurrentDateTime(&v2, &v3);
         v1->unk_174 = v2.year + v2.month * 0x100 * v2.day * 0x10000 + v3.hour * 0x10000 + (v3.minute + v3.second) * 0x1000000 + gCoreSys.frameCounter;
     }
 
@@ -269,7 +269,7 @@ void sub_020521B8 (BattleParams * param0, const UnkStruct_0203CDB0 * param1, Sav
         {
             UnkStruct_02055BA8 * v7 = sub_02025CD8(param2);
 
-            param0->unk_138 = sub_02013974(v7->unk_14.hour);
+            param0->unk_138 = TimeOfDayForHour(v7->unk_14.hour);
         }
     }
 
diff --git a/src/unk_02052C6C.c b/src/unk_02052C6C.c
index 32d14b292d..e45439e02d 100644
--- a/src/unk_02052C6C.c
+++ b/src/unk_02052C6C.c
@@ -27,7 +27,7 @@
 #include "unk_0200B358.h"
 #include "unk_0200DA60.h"
 #include "unk_0200F174.h"
-#include "unk_0201378C.h"
+#include "rtc.h"
 #include "heap.h"
 #include "unk_02018340.h"
 #include "gx_layers.h"
@@ -85,7 +85,7 @@ static void sub_02052C6C (UnkStruct_0203CDB0 * param0, BOOL param1)
 
     v1 = Party_GetFromSavedata(param0->unk_0C);
 
-    sub_020138A4(&v2);
+    GetCurrentDate(&v2);
     sub_0202DFA8(v0, v1, &v2);
     SaveData_SaveHallOfFame(param0->unk_0C, v0);
     Heap_FreeToHeap(v0);
diff --git a/src/unk_020553DC.c b/src/unk_020553DC.c
index 3c22e64821..e80928e273 100644
--- a/src/unk_020553DC.c
+++ b/src/unk_020553DC.c
@@ -9,7 +9,7 @@
 
 #include "unk_020041CC.h"
 #include "unk_02005474.h"
-#include "unk_0201378C.h"
+#include "rtc.h"
 #include "map_header.h"
 #include "unk_0203A6DC.h"
 #include "unk_020507CC.h"
@@ -185,7 +185,7 @@ u16 sub_020554A4 (UnkStruct_0203CDB0 * param0, int param1)
 {
     u16 v0, v1;
 
-    if (sub_02013948() == 0) {
+    if (IsNight() == 0) {
         v0 = MapHeader_GetDayMusicID(param1);
     } else {
         v0 = MapHeader_GetNightMusicID(param1);
diff --git a/src/unk_020559DC.c b/src/unk_020559DC.c
index c787cdbac2..2a5f9b35c9 100644
--- a/src/unk_020559DC.c
+++ b/src/unk_020559DC.c
@@ -10,7 +10,7 @@
 #include "struct_defs/struct_0203CDB0.h"
 #include "struct_defs/struct_02055BA8.h"
 
-#include "unk_0201378C.h"
+#include "rtc.h"
 #include "savedata/save_table.h"
 #include "unk_02025CB0.h"
 #include "unk_0202854C.h"
@@ -45,7 +45,7 @@ void sub_020559DC (UnkStruct_0203CDB0 * param0)
         return;
     }
 
-    sub_0201384C(&v0, &v1);
+    GetCurrentDateTime(&v0, &v1);
     sub_02055A14(param0, v2, &v0);
 
     inline_020559DC(param0, v2, &v0, &v1);
@@ -154,7 +154,7 @@ static void sub_02055B64 (UnkStruct_0203CDB0 * param0, s32 param1, const RTCTime
 int sub_02055BA8 (const UnkStruct_0203CDB0 * param0)
 {
     UnkStruct_02055BA8 * v0 = sub_02025CD8(param0->unk_0C);
-    return sub_02013974(v0->unk_14.hour);
+    return TimeOfDayForHour(v0->unk_14.hour);
 }
 
 int sub_02055BB8 (const UnkStruct_0203CDB0 * param0)
@@ -203,7 +203,7 @@ void sub_02055C2C (const UnkStruct_0203CDB0 * param0)
 {
     UnkStruct_02055BA8 * v0 = sub_02025CD8(param0->unk_0C);
 
-    v0->unk_2C = sub_020138EC();
+    v0->unk_2C = GetTimestamp();
 }
 
 BOOL sub_02055C40 (UnkStruct_0203CDB0 * param0)
diff --git a/src/unk_020562F8.c b/src/unk_020562F8.c
index ce45053df2..7518dd18fe 100644
--- a/src/unk_020562F8.c
+++ b/src/unk_020562F8.c
@@ -12,7 +12,7 @@
 #include "overlay006/battle_params.h"
 
 #include "narc.h"
-#include "unk_0201378C.h"
+#include "rtc.h"
 #include "heap.h"
 #include "savedata/save_table.h"
 #include "unk_0202CD50.h"
@@ -64,15 +64,15 @@ void sub_020562F8 (UnkStruct_0203CDB0 * param0)
     sub_0205642C(param0, v1);
     sub_020564D0(v1);
 
-    v1->unk_40 = sub_020138EC();
+    v1->unk_40 = GetTimestamp();
 }
 
 void sub_02056328 (UnkStruct_0203CDB0 * param0)
 {
     UnkStruct_020564B4 * v0 = &Unk_021C07FC;
     UnkStruct_0202CD88 * v1 = sub_0202CD88(param0->unk_0C);
-    s64 v2 = sub_020138EC();
-    s64 v3 = sub_0201398C(v0->unk_40, v2);
+    s64 v2 = GetTimestamp();
+    s64 v3 = TimeElapsed(v0->unk_40, v2);
 
     if (v3 < 1000) {
         v0->unk_48 = ((1000 - v3) * 2);
diff --git a/src/unk_0206A8DC.c b/src/unk_0206A8DC.c
index 53590996a1..3023485f05 100644
--- a/src/unk_0206A8DC.c
+++ b/src/unk_0206A8DC.c
@@ -3,7 +3,7 @@
 
 #include "struct_decls/struct_020507E4_decl.h"
 
-#include "unk_0201378C.h"
+#include "rtc.h"
 #include "unk_020507CC.h"
 #include "unk_0206A8DC.h"
 
@@ -273,7 +273,7 @@ u16 sub_0206AB68 (UnkStruct_020507E4 * param0, int param1)
     case 494:
     case 497:
         if (sub_0206A8EC(param0, (2400 + 37)) == 1) {
-            if (sub_02013948() == 0) {
+            if (IsNight() == 0) {
                 v0 = 1016;
             } else {
                 v0 = 1045;
@@ -292,7 +292,7 @@ u16 sub_0206AB68 (UnkStruct_020507E4 * param0, int param1)
     case 74:
     case 75:
         if (sub_0206A8EC(param0, (2400 + 39)) == 1) {
-            if (sub_02013948() == 0) {
+            if (IsNight() == 0) {
                 v0 = 1013;
             } else {
                 v0 = 1042;
@@ -301,7 +301,7 @@ u16 sub_0206AB68 (UnkStruct_020507E4 * param0, int param1)
         break;
     case 201:
         if (sub_0206A8EC(param0, (2400 + 40)) == 1) {
-            if (sub_02013948() == 0) {
+            if (IsNight() == 0) {
                 v0 = 1023;
             } else {
                 v0 = 1052;
@@ -310,7 +310,7 @@ u16 sub_0206AB68 (UnkStruct_020507E4 * param0, int param1)
         break;
     case 256:
         if (sub_0206A8EC(param0, (2400 + 41)) == 1) {
-            if (sub_02013948() == 0) {
+            if (IsNight() == 0) {
                 v0 = 1006;
             } else {
                 v0 = 1035;
@@ -319,7 +319,7 @@ u16 sub_0206AB68 (UnkStruct_020507E4 * param0, int param1)
         break;
     case 399:
         if (sub_0206A8EC(param0, (2400 + 42)) == 1) {
-            if (sub_02013948() == 0) {
+            if (IsNight() == 0) {
                 v0 = 1006;
             } else {
                 v0 = 1035;
diff --git a/src/unk_02092494.c b/src/unk_02092494.c
index ff00950354..7d255f3beb 100644
--- a/src/unk_02092494.c
+++ b/src/unk_02092494.c
@@ -5,7 +5,7 @@
 
 #include "message.h"
 #include "unk_0200B358.h"
-#include "unk_0201378C.h"
+#include "rtc.h"
 #include "unk_02017038.h"
 #include "heap.h"
 #include "strbuf.h"
@@ -835,7 +835,7 @@ static void sub_020932F0 (BoxPokemon * param0, int param1, int param2)
 {
     RTCDate v0;
 
-    sub_020138A4(&v0);
+    GetCurrentDate(&v0);
 
     if (param2 == 0) {
         BoxPokemon_SetValue(param0, 152, &param1);
diff --git a/src/unk_020933F8.c b/src/unk_020933F8.c
index 69b1f8623a..329da8ec61 100644
--- a/src/unk_020933F8.c
+++ b/src/unk_020933F8.c
@@ -35,7 +35,7 @@
 #include "unk_0200A9DC.h"
 #include "unk_0200B358.h"
 #include "unk_0200D9E8.h"
-#include "unk_0201378C.h"
+#include "rtc.h"
 #include "heap.h"
 #include "unk_0201D15C.h"
 #include "strbuf.h"
@@ -1703,7 +1703,7 @@ void sub_02094C44 (UnkStruct_02095C48 * param0, SaveData * param1, u32 param2, U
 
 static void sub_02094E7C (UnkStruct_02095C48 * param0)
 {
-    LCRNG_SetSeed((sub_020138C8() * (LCRNG_GetSeed() + 10)) & 0xffff);
+    LCRNG_SetSeed((GetSecondsSinceMidnight() * (LCRNG_GetSeed() + 10)) & 0xffff);
 }
 
 u16 sub_02094E98 (UnkStruct_02095C48 * param0)