query filter on date portion of datetime creates wrong parameters for mysql CONVERT_TZ function when used with a fixed offset timezone

[donaldinho]

I am setting the timezone

tz = timezone.get_fixed_timezone(-300)
timezone.activate(tz)

then I apply the filter. search_date is just a string submitted by the client

matches = query.filter(startDateTime__date=datetime.strptime(search_date, '%Y-%m-%d').date())

the where clause that is produced is

DATE(CONVERT_TZ(`match`.`startDateTime`, 'UTC', '-0500')) = '2017-07-18'

where as it should be

DATE(CONVERT_TZ(match`.`startDateTime`, 'UTC', '-05:00')) = '2017-07-18'

note the colon in the timezone we are converting to.

[Tim Graham]

I can reproduce the problem, although poking around the code left me wondering if there's a reason not to deprecate get_fixed_timezone() and FixedOffset so we don't have to handle this additional case. Is there a reason you're preferring that rather than using pytz? I didn't see an explanation of the get_fixed_timezone()'s use case in Django's documentation.

[donaldinho]

I think I used get_fixed_timezone because I had the clients offset provided by javascript in minutes rather than an explicit timezone and I couldn't see a way to create a tzinfo class any other way

[Can Sarıgöl]

In master branch, I couldn't see a problem with this query. Doesn't timedelta(hours=-5) work for your need? am I wrong?