use local date functions

These are the replacements.

  datetime.date() -> localdate().date()
  datetime.date.today() -> localtoday().date()
  datetime.datetime() -> localdatetime()
  datetime.datetime.now() -> localnow()
  datetime.datetime.today() -> localnow()

Change-Id: I1f8eda4dce8f48483649f0005ab576c5b1d71a1a