33

TL;DR;

How to convert 2016-01-01 to Django timezone?

Full version:

I receive a query string parameter from a form and I wanna get that string and use it as a datetime filter in Django. The problem is that when I convert the string to a datetime, it's not making an aware datetime and so I lose a few hours due to timezone different. Maybe I'm losing myself in the formatting, but I'm not being able to do it.

I have pytz, I have USE_TZ = True in my settings as well.

example:

from datetime import date
# Example from what I receive as GET querystring parameter
start_date, end_date = '15-01-2016', '16-01-2016'
DATE_FORMAT = '%Y-%m-%d'
start_date = start_date.split('-')
start_date = date(int(start_date[2]), int(start_date[1]), int(start_date[0]))
sd_filter = start_date.strftime(DATE_FORMAT)

end_date = end_date.split('-')
end_date = date(int(end_date[2]), int(end_date[1]), int(end_date[0]))
ed_filter = end_date.strftime(DATE_FORMAT)

#query
my_list = MyModel.objects.filter(created_at__range=(sd_filter, ed_filter))

the problem lies in the filter. I'm losing a few hours due to timezone from Django settings.

UPDATE: I don't need to convert a datetime.now() to my time. I need to convert a string to datetime.

funnydman
  • 9,083
  • 4
  • 40
  • 55
jarussi
  • 1,491
  • 1
  • 13
  • 25
  • What field type are you using in your model? A `DateField()`? If so, you can just pass the two `date` objects (`start_date` and `end_date`) to your `created_at__range=()` filter. – gtlambert Jan 15 '16 at 18:10
  • 1
    Possible duplicate of [Python Timezone conversion](http://stackoverflow.com/questions/10997577/python-timezone-conversion) – Lajos Arpad Jan 15 '16 at 18:11
  • @lambo477 It's a `DateTimeField` and I tryed doing that .. but it's still missing a few hours from utc. – jarussi Jan 15 '16 at 18:43
  • @LajosArpad I tried using what was said in the answers but it didn't work for me :( – jarussi Jan 15 '16 at 18:50

3 Answers3

66

I know this is old but maybe will be helpful since I got into this situation as well:

What about using make_aware() ?

from datetime import datetime
from django.utils.timezone import make_aware

date = '22-05-2018'
aware = make_aware(datetime.strptime(date, '%d-%m-%Y'))

This will use the currently active timezone (activated by timezone.activate). If no timezone is activated explicitly, it would use the default timezone -- TIME_ZONE specified in settings.py.

heemayl
  • 39,294
  • 7
  • 70
  • 76
Gustavo A. Díaz
  • 778
  • 1
  • 7
  • 10
23

You are comparing time-zone unaware Python Date objects with the time-zone aware DateTimeField fields in your database. It is probably more intuitive to use DateTime objects - and these can be made time-zone aware easily as follows:

import datetime
import pytz

start_date = '15-01-2016' 
end_date = '16-01-2016'
date_format = '%d-%m-%Y'

unaware_start_date = datetime.datetime.strptime(start_date, date_format)
aware_start_date = pytz.utc.localize(unaware_start_date)

unaware_end_date = datetime.datetime.strptime(end_date, date_format)
aware_end_date = pytz.utc.localize(unaware_end_date)

my_list = MyModel.objects.filter(created_at__range=(aware_start_date, aware_end_date))

This creates unaware_start_date and unaware_end_date DateTime objects using strptime(). It then uses pytz.utc.localize to make the objects time-zone aware (you will need to replace utc with your relevant time-zone).

You can then have time-zone aware DateTime objects - aware_start_date and aware_end_date. Feeding these into your filter should yield the desired results.

gtlambert
  • 11,711
  • 2
  • 30
  • 48
3
from django.utils import timezone
timestamp_raw = timezone.now() #current time, or use whatever time you have
date_format = '%Y-%m-%d %H:%M:%S' #time format day-month-year hour:minutes:seconds
timestamp = timezone.datetime.strftime(timestamp_raw, date_format)

Or Using the new f-string formatter

f"{timezone:%Y-%m-%d %H:%M:%S %p}"
salafi
  • 387
  • 6
  • 9