def add_interval_to_datetime(interval, dt):
"""
Add a timedelta or isodate.Duration to a datetime and return the result.
This is a workaround to a bug in isodate 0.4.7-0.4.8 that prevents Duration
instances from being added to datetime instances.
@param interval: interval to add to the datetime instance
@param dt: datetime instance
@return: new datetime instance with interval added
@rtype: datetime.datetime
"""
assert isinstance(interval, (datetime.timedelta, isodate.Duration))
assert isinstance(dt, datetime.datetime)
if isinstance(interval, datetime.timedelta):
return interval + dt
new_month = dt.month + interval.months
year_carry, new_month = fquotmod(new_month, 1, 13)
new_year = dt.year + interval.years + year_carry
max_days = max_days_in_month(new_year, new_month)
new_day = min(max_days, dt.day)
new_dt = dt.replace(year=int(new_year), month=int(new_month), day=int(new_day))
return interval.tdelta + new_dt
def add_interval_to_datetime(interval, dt):
"""
Add a timedelta or isodate.Duration to a datetime and return the result.
This is a workaround to a bug in isodate 0.4.7-0.4.8 that prevents Duration
instances from being added to datetime instances.
@param interval: interval to add to the datetime instance
@param dt: datetime instance
@return: new datetime instance with interval added
@rtype: datetime.datetime
"""
assert isinstance(interval, (datetime.timedelta, isodate.Duration))
assert isinstance(dt, datetime.datetime)
if isinstance(interval, datetime.timedelta):
return interval + dt
new_month = dt.month + interval.months
year_carry, new_month = fquotmod(new_month, 1, 13)
new_year = dt.year + interval.years + year_carry
max_days = max_days_in_month(new_year, new_month)
new_day = min(max_days, dt.day)
new_dt = dt.replace(year=int(new_year), month=int(new_month), day=int(new_day))
return interval.tdelta + new_dt