Rotate csv annually, put it in log directory with backup text log

.gitignore

@@ -1,2 +1,2 @@
 log/*.log
-timelog.csv
+log/*.csv

pomodoroprompt.py

@@ -53,12 +53,7 @@ def quit_prompt():
 def log_step(text, utc_start, end_section=False):
     """ Write detailed log of all events
     """
-    eastern = timezone('US/Eastern')
-    start = utc_start.astimezone(eastern)
-    timelog_path = 'log/' + str(start.year) + '-' \
-        + format(start.month, '02') + '-' \
-        + format(start.day, '02') + '.log'
-    timelog_file = Path(timelog_path)
+    timelog_file = Path(timelog_path(ext='log', daily=True))
     timelog_file.touch(exist_ok=True)
     with timelog_file.open('a') as timelog:
         timelog.write(text + '\n')
@@ -71,7 +66,7 @@ def record_task(whatnext, whatdid, start, end=None):
     """
     if end is None:
         end = datetime.now(pytz.utc)
-    with open('log/timelog.csv', 'a', newline='') as csvfile:
+    with open(prepare_file(), 'a', newline='') as csvfile:
         # TODO make first line started, recorded, description, intention
         timewriter = csv.writer(csvfile)
         timewriter.writerow([start, end, whatdid, whatnext])
@@ -89,6 +84,22 @@ def countdown_to(until):
         print('\r', str_minutes(to_go), sep='', end='')
         time.sleep(1)
 
+def prepare_file(ext='csv', daily=False, utc_start):
+    # Ensure log directory exists.
+    if not os.path.exists('log'):
+        os.makedirs('log')
+    # We consider 3am the switchover to a new day, so we skip extra math
+    # and use Pacific time to get three hours later than our Eastern time.
+    logpath_tz = timezone('US/Pacific')
+    logpath_date = utc_start.astimezone(logpath_tz)
+    timelog_path = 'log/' + str(logpath_date.year);
+    if (daily):
+        timelog_path += '-' \
+        + format(logpath_date.month, '02') + '-' \
+        + format(logpath_date.day, '02') + '.log'
+    timelog_path += '.' + ext
+    return timelog_path
+
 def main():
     whatdid = ''
     while True: