Fully cover the Gregorian Calendar with tests

Being one of the cornerstones right now, it deserves a lot of tests

calsocial/calendar_system/gregorian.py

@@ -18,24 +18,12 @@
 """
 
 from datetime import datetime, timedelta
-from functools import wraps
 
 from flask_babelex import lazy_gettext as _
 
 from . import CalendarSystem
 
 
-def to_timestamp(func):
-    """Decorator that converts the return value of a function from `datetime` to a UNIX timestamp
-    """
-
-    @wraps(func)
-    def _decorator(*args, **kwargs):
-        return func(*args, **kwargs).timestamp()
-
-    return _decorator
-
-
 class GregorianCalendar(CalendarSystem):
     """Gregorian calendar system for Calendar.social
     """
@@ -104,7 +92,6 @@ class GregorianCalendar(CalendarSystem):
         return day_list
 
     @property
-    @to_timestamp
     def prev_year(self):
         """Returns the timestamp of the same date in the previous year
         """
@@ -119,7 +106,6 @@ class GregorianCalendar(CalendarSystem):
         return self.timestamp.replace(year=self.timestamp.year - 1).year
 
     @property
-    @to_timestamp
     def prev_month(self):
         """Returns the timestamp of the same day in the previous month
         """
@@ -142,7 +128,6 @@ class GregorianCalendar(CalendarSystem):
         return self.month_names[timestamp.month - 1]
 
     @property
-    @to_timestamp
     def next_month(self):
         """Returns the timestamp of the same day in the next month
         """
@@ -165,7 +150,6 @@ class GregorianCalendar(CalendarSystem):
         return self.month_names[timestamp.month - 1]
 
     @property
-    @to_timestamp
     def next_year(self):
         """Returns the timestamp of the same date in the next year
         """
@@ -198,7 +182,7 @@ class GregorianCalendar(CalendarSystem):
 
         month_end_timestamp = month_start_timestamp.replace(month=next_month)
 
-        return now >= month_start_timestamp and now < month_end_timestamp
+        return month_start_timestamp <= now < month_end_timestamp
 
     @staticmethod
     def day_events(date, user=None):