Account Move post_date stored is diferent with the realy date that was posted

I am in the time zone America/Bogota (-5) and if I Post a Account Move (account.move) after the 19:00 (in my timezone) the field move.post_date(http://hg.tryton.org/modules/account/file/tip/move.py#l409) stored has a difference of one day with the date that was posted.

I think this is about converting an datetime object to a date object(http://hg.tryton.org/trytond/file/tip/trytond/ir/date.py#l29) and that this difference varies depending on the time zone.

Is this the expected behavior?

Note: that topic may be related to this topic Change most Date fields by DateTime

Are you sure you have setup the timezone on the company?

Thank you ced, The company did not have configured the time zone.