id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
32249	Increment of duration field not works properly	Alex Zaitsev	nobody	"I have a duration field in some model:

{{{
My(models.Model):
   ...
   duration = models.DurationField(default=timedelta(seconds=0))
}}}

and I try to increment durations via F expression:

{{{
obj.duration = F('duration') + (now - some_other_datetime)
}}}

as a result, we have a value of the following format in the database: 0:18:30.233251 instead of a big integer one. So this makes that instance of model completely unusable, any attempt of access raise an exception: TypeError: unsupported type for timedelta microseconds component: str"	Bug	closed	Database layer (models, ORM)	3.1	Normal	duplicate	duration		Unreviewed	0	0	0	0	0	0