Libfaketime
From charlesreid1
$ faketime '2008-12-25 08:00:00' python Python 2.7.10 (v2.7.10:15c95b7d81dc, May 23 2015, 09:33:12) [GCC 4.2.1 (Apple Inc. build 5666) (dot 3)] on darwin Type "help", "copyright", "credits" or "license" for more information. >>> import datetime >>> print datetime.datetime.now() 2008-12-25 08:00:12.829915 >>>