diff --git a/forest/oak/base.py b/forest/oak/base.py
index fcb02f81..d5925613 100644
--- a/forest/oak/base.py
+++ b/forest/oak/base.py
@@ -528,7 +528,7 @@ def run_hourly(
         cadence_temp = cadence_bout[t_hours_pd == t_unique]
         cadence_temp = cadence_temp[cadence_temp > 0]
         # store hourly metrics
-        if math.isnan(steps_hourly[ind_to_store]):
+        if math.isnan(steps_hourly[ind_to_store].item()):
             steps_hourly[ind_to_store] = int(np.sum(cadence_temp))
             walkingtime_hourly[ind_to_store] = len(cadence_temp)
         else:
@@ -613,11 +613,11 @@ def run(study_folder: str, output_folder: str, tz_str: Optional[str] = None,
                 frequency == Frequency.HOURLY_AND_DAILY
                 or frequency == Frequency.HOURLY
             ):
-                freq = 'H'
+                freq = 'h'
             elif frequency == Frequency.MINUTE:
-                freq = 'T'
+                freq = 'min'
             else:
-                freq = str(frequency.value/60) + 'H'
+                freq = str(frequency.value/60) + 'h'
 
             days_hourly = pd.date_range(date_start, date_end+timedelta(days=1),
                                         freq=freq)[:-1]
diff --git a/forest/oak/tests/test_run_hourly.py b/forest/oak/tests/test_run_hourly.py
index 242b52bd..3c392655 100644
--- a/forest/oak/tests/test_run_hourly.py
+++ b/forest/oak/tests/test_run_hourly.py
@@ -23,7 +23,7 @@ def sample_run_input(signal_bout):
     t_ind_pydate = pd.date_range(
         start='2020-02-24 00:00:00',
         end='2020-02-25 23:00:00',
-        freq='H',
+        freq='h',
         tz='US/Eastern'
     ).to_pydatetime()
     cadence_bout = np.array(