https://bugzilla.wikimedia.org/show_bug.cgi?id=71124
--- Comment #2 from xqt info@gno.de --- The problem is that months have different days between 28 an 31. Adding 1 month to 7th September should result in 7th October. Adding 7th October should give 7th November as result. dateutils does it. The highest timedelta resolution is "days" not "months". We could use constants from calendar module to implement it. I need it to calculate log entries. mw is able to calculate time stamps by adding months and years, whereas datetime objects aren't able to.