diff --git a/CHANGELOG b/CHANGELOG
index a36cb2e..220301a 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,6 +1,8 @@
 # 0.7.0
 
-tick.interval.bounds function is now consistent for years, year-months and dates in setting the `end` to be inclusive
+* tick.interval.bounds function is now consistent for years, year-months and dates in setting the `end` to be inclusive
+* Strings are no longer accepted as beginning/end when constructing an interval
+* Strings are no longer accepted as arguments to clock
 
 # 0.6.1 
 
diff --git a/docs/intervals.adoc b/docs/intervals.adoc
index fd0d249..204bdc7 100644
--- a/docs/intervals.adoc
+++ b/docs/intervals.adoc
@@ -24,8 +24,8 @@ Here we use a literal map syntax to construct an interval representing the last
 
 [source.code,clojure]
 ----
-{:tick/beginning "2018-12-31T23:55:00Z"
- :tick/end "2019-01-01T00:00:00Z"}
+{:tick/beginning (t/instant "2018-12-31T23:55:00Z")
+ :tick/end (t/instant "2019-01-01T00:00:00Z"})
 ----
 
 ====
diff --git a/src/tick/core.cljc b/src/tick/core.cljc
index 4c0a483..be7fcb7 100644
--- a/src/tick/core.cljc
+++ b/src/tick/core.cljc
@@ -718,10 +718,7 @@
   (clock [clk] clk)
 
   ZoneId
-  (clock [z] (cljc.java-time.clock/system z))
-
-  #?(:clj String :cljs string)
-  (clock [s] (p/clock (p/parse s))))
+  (clock [z] (cljc.java-time.clock/system z)))
 
 (defn tick-resolution
   ([clk]
@@ -923,10 +920,6 @@
     ([from to step] (cond->> (iterate #(cljc.java-time.year/plus % step) from)
                       to (take-while #(p/< % to))))))
 
-(extend-protocol p/IDivisible
-  #?(:clj String :cljs string)
-  (divide [s d] (p/divide (p/parse s) d)))
-
 (extend-protocol p/IDivisibleDuration
   #?(:clj Long :cljs number)
   (divide-duration [n duration] (cljc.java-time.duration/divided-by duration n))
@@ -965,8 +958,6 @@
   (between [v1 v2] (cljc.java-time.duration/between v1 (p/offset-date-time v2)))
   #?@(:clj [Temporal
             (between [v1 v2] (cljc.java-time.duration/between v1 v2))])
-  #?(:clj String :cljs string)
-  (between [v1 v2] (p/between (p/parse v1) (p/parse v2)))
   #?(:clj Date :cljs js/Date)
   (between [x y] (p/between (p/instant x) (p/instant y))))