Add time.date_range() convenience function

rattail/time.py

@@ -170,3 +170,13 @@ def last_of_month(date):
     """
     last_day = calendar.monthrange(date.year, date.month)[1]
     return date.replace(day=last_day)
+
+
+def date_range(start, end, step=1):
+    """
+    Generator which yields all dates between ``start`` and ``end``, *inclusive*.
+    """
+    date = start
+    while date <= end:
+        yield date
+        date += datetime.timedelta(days=step)