I am creating a form in Django. I have to put a input type field, which only stores the timezone in database(which will be chosen by a user from a drop Down list at form). I am not able to find out any approach to create this timezone model and how it will return the local time according to saved timezone. I choose following field but it stores also minute hours and second also
timestamp = models.DateTimeField()
Drop down list should be in form of :
...
GMT +5:30
GMT +6:00...and so on.
I think the above answers are all correct, but I leave mine here as an simple example...
class UserProfile(models.Model):
import pytz
TIMEZONES = tuple(zip(pytz.all_timezones, pytz.all_timezones))
# ...
timezone = models.CharField(max_length=32, choices=TIMEZONES,
default='UTC')
# ...
Neither django nor python provide a set of timezones for you to use.
For that, you will need an additional module like pytz. You can get a list of all timezones like this:
>>> import pytz
>>> pytz.all_timezones ['Africa/Abidjan', 'Africa/Accra', 'Africa/Addis_Ababa', 'Africa/Algiers', 'Africa/Asmara',
'Africa/Asmera'....
You can their store the timezone name in a CharField.
By the way, choosing a timezone by "GMT +6:00" is not a good idea. For example, EST is usually 5 hours behind GMT, but for 2 weeks around daylight savings time changes, the offset is different. Also, at some times of year someone in Queensland and someone in New South Wales both have the same GMT offset, but because NSW has DST and Queensland doesn't, for half the year their GMT offsets are different. The only safe way to list timezones is to list the actual geographic timezones.
django-timezone-field is an app that handles this nicely.
The way I do this is using pytz valid timezone names. I adjusted my list to reflect only the ones I need, i.e.
TIMEZONES = (
'Canada/Atlantic',
'Canada/Central',
'Canada/Eastern',
'Canada/Mountain',
'Canada/Pacific',
)
I then have a location class which sets the timezone as a Char Field as such:
class Location(models.Model):
....
time_zone = models.CharField(max_length=100, blank=True, null=True, choices=TIMEZONES) # 64 min
....
Notice I set blank & null to True to make the field optional. Take a look at django-timezone-field fields.py for further ideas.
To use this in my code with pytz, I import timezone:
from pytz import timezone
import datetime
from locations.models import Location # my object that has the time_zone field
loc = Location.objects.get(pk=1) #get existing location or your object that has time_zone field
utc = pytz.utc
some_utc_date = datetime.datetime(2002, 10, 27, 6, 0, 0).replace(tzinfo=utc) #tz aware
some_date.astimezone(timezone(loc.time_zone))
Replace datetime.datetime(2002, 10, 27, 6, 0, 0) with the datetime field that corresponds to your location or specific object that has the time_zone field. In my case I store all my date fields in UTC format in a MongoDB collection. When I retrieve the data and want to create human readable output, I use the above method to show the date in the output. You can also create a custom tag to handle this in templates. See pytz doc for more details.
If you are migrating from pytz to zoneinfo:
try:
import zoneinfo
except ImportError:
from backports import zoneinfo
class UserProfile(models.Model):
TIMEZONE_CHOICES = ((x, x) for x in sorted(zoneinfo.available_timezones(), key=str.lower))
timezone = models.CharField("Timezone", choices=TIMEZONE_CHOICES, max_length=250, default='Etc/GMT+2')
Related
I want to store time as unix timestamp in my MYSQL database, I have django project with model:
date = models.DateField()
But I didn't find any models.Timestamp()
or anything similiar. Is there a way to create timestamp column for MYSQL Db in Django? I found some articles here on stack but they are 5+ years old so there might a be a better solution now.
In Django, one usually uses a DateTimeField [Django-doc] for that. It is a column that thus stores a combination of date and time.
One can let Django automatically intialize (or update) the timestamp if the record is constructed or updated with auto_now_add=True [Django-doc] to initialize it when the record was created, and auto_now=True [Django-doc] to update. So it is a common pattern to see a (base)model like:
class TimestampModel(models.Model):
created = models.DateTimeField(auto_now_add=True)
updated = models.DateTimeField(auto_now=True)
class Meta:
abstract = True
such that subclasses of the TimestampModel thus have two extra columns created and updated that store the time when the object was created and last updated respectively.
A datetime column has a larger range, as is specified in the MySQL documentation:
The DATETIME type is used for values that contain both date and time
parts. MySQL retrieves and displays DATETIME values in 'YYYY-MM-DD hh:mm:ss' format. The supported range is '1000-01-01 00:00:00' to
'9999-12-31 23:59:59'.
The TIMESTAMP data type is used for values that contain both date
and time parts. TIMESTAMP has a range of '1970-01-01 00:00:01' UTC to '2038-01-19 03:14:07' UTC.
I'm developing a Django app for logging dives and each dive has a datetime and a timezone in it. I'm using the django-timezone-field app for the timezone.
class Dive(models.Model):
...
date_time_in = models.DateTimeField(default=timezone.now)
timezone = TimeZoneField(default=timezone.get_current_timezone_name())
So the user is able to enter a datetime string ("2016-07-11 14:00") and select a timezone ("Asia/Bangkok" - UTC+0700), I then set the timezone of the datetime to the one given in my view like this:
def log_dive(request):
if request.method == 'POST':
form = DiveForm(request.POST)
if form.is_valid():
dive = form.save(commit=False)
date = dive.date_time_in
date = date.replace(tzinfo=None)
dive.date_time_in = dive.timezone.localize(date)
dive.save()
The database then stores the datetime as UTC in the database (SELECT statement gives it in my local timezone):
# SELECT date_time_in, timezone FROM divelog_dive ORDER BY number DESC;
date_time_in | timezone
------------------------+------------------
2014-07-11 17:00:00+10 | Asia/Bangkok
Now there are two things I'm struggling with:
1) I want to display the dates in the given timezone, however I can't seem to stop it defaulting to the TIME_ZONE setting.
2) If the user edits the record, the time displayed in the edit field should be the one they originally entered (14:00), instead it's showing it in the current timezone (17:00).
Check your timezone setting in settings.py
Do you have USE_TZ = true in your settings file? If you created your app using the djangoadmin-startproject command, it is set by default.
Also, I struggled with timezones at my last job but found that using pytz really helped. Have you tried that package yet?
EDIT: Ok man I may be way off, but since noone else has answered and I feel the timezone struggle, here is something I noticed...
You are replacing the date object with tz_info=None, but wouldn't you want to instead replace that with the timezone from the database? So you would get that timezone and do a replace using the valid format (tzinfo=blah...)?
Like I said I may be way off but if that helps there you go.
Sorry, I don't think I explained my problem very well. I finally figured this out, so I'll answer my own question.
1) turned out to be easy, Django have a template tag for displaying times in a given zone:
{{ dive.date_time_in|timezone:dive.timezone|date:"Y-m-d H:i e" }}
For 2), I came across [1] which lead me to this solution: In the view, after getting the object from the database, I use astimezone(...) to convert the date value (which the DB stores as UTC) into the given timezone. I then use replace(tzinfo=None) to make it naive and then it displays correctly on my form.
def edit_dive(request, dive_id=None):
dive = None
if dive_id != None:
dive = get_object_or_404(Dive, pk=dive_id)
local_date = dive.date_time_in.astimezone(timezone(str(dive.timezone)))
dive.date_time_in = local_date.replace(tzinfo=None)
[1] http://www.saltycrane.com/blog/2009/05/converting-time-zones-datetime-objects-python/
I saw this post Is Django corrupting timezone-aware DateTimeField when saving it to the Database? but it specifically uses pytz and mysql and what not where I don't use pytz and use SQLite (incase it might have an impact).
I have the following model
class ScheduleItem(models.Model):
work_date = models.DateTimeField('Work date')
And I insert data as follows:
from isoweek import Week
from dateutil import parser
from django.utils import timezone
def foo()
year = 2016 #hardcoded for example purpose
wknr = 2 #hardcoded for example purpose
dateObj = parser.parse(Week(year, wknr).day(0).isoformat() + " 00:00:00")
print(dateObj) # 2016-01-11 00:00:00 as expected
final = timezone.make_aware(dateObj)
print(final) # 2016-01-11 00:00:00+01:00 as expected
return final
workdate = foo()
si = ScheduleItem(work_date=workdate)
si.save()
The print statements give me the right output, however once I look in the database (SQLite) I see 2016-01-10 23:00:00
My django settings say
TIME_ZONE = 'CET'
USE_TZ = True
Retrieving the data I get:
datetime.datetime(2016, 1, 10, 23, 0, tzinfo=<UTC>)
Why is it storing the data in another format then I specify and why if Django is set to be timezone aware do I get a UTC timezone back? I mean before insertion the datetime object says: datetime.datetime(2016, 1, 11, 0, 0, tzinfo=<DstTzInfo 'CET' CET+1:00:00 STD>)
update -
I found a work around in the meantime by setting TIME_ZONE on the database as described in the Django documentation here. This gives me the right timezone/date in the database, but according to that documentation I shouldn't need it because my DB is managed by Django
This allows interacting with third-party databases that store datetimes in local time rather than UTC. To avoid issues around DST changes, you shouldn’t set this option for databases managed by Django.
It is still unclear to me why Django does convert a datetime object with a CET timezone to UTC when storing it in the database, but isn't smart enough to convert it back to CET when retrieving.
Django uses UTC time internally. TIME_ZONE will be used "for your views and models" (https://docs.djangoproject.com/en/1.9/ref/settings/#std:setting-TIME_ZONE)
You started with 2016-01-11 00:00 CET, which is 2016-01-10 23:00 UTC! Your datetime was correctly saved to the database and later restored, so everything is working as expected.
I have the following model class
class Transaction(models.Model):
quantity = models.IntegerField(default=0)
sell_time = models.DateTimeField()
When I fetch "sell_time" from the model, I am getting datetime in the following format
2014-10-01 08:09:46.251563+00:00
my question is, if it is not in the format like
year-month-day hour:minutes:seconds
how can I convert to python datetime object like
datetime.datetime(2014, 10, 1, 08, 09, 46, 540535)
many thanks
Did you print it? If you print a datetime object, it is serialized to a string but it is a datetime. You can use it as any other datetime.
You are seeing that because you did not set the correct time zone. Use the UTC time and then you can format .strftime("format") the time accordingly to each locale, you can install pytz and enable it in the settings to handle all the hustle. Always use UTC datetime object because then you can get what ever time you want knowing the zone your user is in. Documentation from Django
I have a model with a datetime field:
class MyModel(models.Model):
created = models.DateTimeField(auto_now = True)
I want to get all the records created today.
I tried:
MyModel.objects.all().filter(created = timezone.now())
and
MyModel.objects.all().filter(created = timezone.now().date())
But always got an empty set. What is the correct way in Django to do this?
EDIT:
It looks strange, but a record, created today (06.04.2012 23:09:44) has date (2012-04-07 04:09:44) in the database. When I'm trying to edit it in the admin panel it looks correct (06.04.2012 23:09:44). Does Django handle it somehow?
Since somewhere in 2015:
YourModel.objects.filter(some_datetime__date=some_date)
i.e. __date after the datetime field.
https://code.djangoproject.com/ticket/9596
There may be a more proper solution, but a quick workup suggests that this would work:
from datetime import timedelta
start_date = timezone.now().date()
end_date = start_date + timedelta( days=1 )
Entry.objects.filter(created__range=(start_date, end_date))
I'm assuming timezone is a datetime-like object.
The important thing is that you're storing an exact time, down to the millisecond, and you're comparing it to something that only has accuracy to the day. Rather than toss the hours, minutes, and seconds, django/python defaults them to 0. So if your record is createed at 2011-4-6T06:34:14am, then it compares 2011-4-6T:06:34:14am to 2011-4-6T00:00:00, not 2011-4-6 (from created date) to 2011-4-6 ( from timezone.now().date() ). Helpful?
Try this
from datetime import datetime
now=datetime.now()
YourModel.objects.filter(datetime_published=datetime(now.year, now.month, now.day))