Time format
"2018-12-13T05:20:06.427Z"
django providing time zone in above format when i am fetching data from database using ORM query.
In my model field is in below way.
models.DateTimeField(auto_now=True, blank=True,null=True)
How can i convert it into "24 feb 2018" like this
Apart from #Sosthenes Kwame Boame answer, you can use strftime for formatting.
import datetime
time = datetime.datetime.now().strftime('%d %b %Y')
Out[13]: '13 Dec 2018'
Instead of passing datetime module to time variable, you should pass your model field's value.
If you want to learn more about format type then you can visit the documentation page.
I am guessing you want to display this on the frontend?
You need to do this in your template:
{{ object_name.datefield_name|date:'j b Y' }}
So you call the datefield and render it with the '|date' tag with a format assigned ':'FORMAT''.
Learn more about the date tag, along with the various formats here: https://docs.djangoproject.com/en/2.1/ref/templates/builtins/#date
Related
I have this code that behaves in a rather strange way and opens the question, how should I deal with timezones? So, first I have a datetime object I build from the info a user posts:
time_zone = request.POST.get("time_zone")
date_start = request.POST.get("date_start")
time_day = request.POST.get("time_day")
time_zone_obj = pytz.timezone("Etc/" + time_zone) # GMT + 2 in this example
date_start = datetime.strptime(date_start, "%d/%m/%Y")
date_start = date_start.replace(tzinfo=time_zone_obj)
time_day = datetime.strptime(time_day, "%I:%M %p")
date_start = date_start.replace(hour=time_day.hour, minute=time_day.minute)
...
event.date_start = date_start
event.save()
print("event.date_start.hour:%s" % event.date_start.hour)
print("event.date_start.tzinfo:%s" % event.date_start.tzinfo)
print("is_aware(event.date_start:%s)" % is_aware(event.date_start))
return redirect("event_detail", event_id=event.id)
This prints event.date_start.hour:6, event.date_start.tzinfo:Etc/GMT+2 and is_aware:True. Then, inmediatlty after saving the object and printing the hour, it redirects to the event_detail view, very simple:
def event_detail(request, event_id):
event = get_object_or_404(Event, id=event_id)
print("event.date_start.hour:%s" % event.date_start.hour)
print("event.date_start.tzinfo:%s" % event.date_start.tzinfo)
...
And it prints event.date_start.hour:8 and event.date_start.tzinfo:UTC. (it has replaced the tz info with UTC) I don't understand why. I am saving the object with a clear tz_info. Plz note that I printed the hour after I saved the object and then after I retrieved it in the other view. It has a difference of two hours that must have something to do with the timezone the user selected (GMT + 2). Why is this? Which is the best way to save this data?
The user submits "6:00 AM" + "GMT+2" in the form and then later when I want to show the time in the event detail html ({{ event.date_start|date:"h:i A" }}) it displays "8:00 AM".
I assume you're using PostgreSQL to save the timezone aware timestamp.
It's important to understand that (contrary to the name and popular belief) PostgreSQL doesn't save the timezone of the timezone aware timestamp. It's just a way to tell PostgreSQL that the value is not in some local time, but is timezone aware.
PostgreSQL then converts it to UTC and stores as such. If the original timezone is important, you need to store it separately.
More info on the topic: https://www.postgresqltutorial.com/postgresql-timestamp/
The best way to store this data is a separate column (usually called timezone). I use https://pypi.org/project/django-timezone-field/
Then either activate timezone (https://docs.djangoproject.com/en/3.1/ref/utils/#django.utils.timezone.activate) or use localtime (https://docs.djangoproject.com/en/3.1/ref/utils/#django.utils.timezone.localtime) util function.
As per the Django docs,
"When support for time zones is enabled, Django stores DateTime information in UTC in the database. It’s still good practice to store data in UTC in your database. The main reason is the Daylight Saving Time (DST). "
So saving DateTime in UTC format in the database as expected.
Now, going ahead with your requirement. In order to display the time back in the timezone which was used for saving you need to add a column in the DB to store the timezone info.
While retrieving the DateTime, convert it into the required timezone back using the tzinfo stored in DB.
This is the correct way of doing. Hope this helps you understand better.
I'm trying to export some data from Django to Excel using openpyxl.
The exported datetimes are correctly interpreted as such in Excel, but their printout is in UTC, not in local timezone (CET in this case) as I'd expect.
I tried to use to_excel, but that only outputs datetimes converted to excel's internal float format. Which is in addition also interpreted as float, not datetime. When formatted as datetime, it's still in UTC
I also tried to use Django's django.utils.timezone.localtime, but again the dates are rendered in UTC.
I could just subtract the timezone offset from my dates, but I feel it's more likely I'm missing something here.
How can I export datetime data such that Excel would display it in my local timezone?
I had the similar problem and solved it in the following way.
May be it helps.
from dateutil.tz import tzutc, tzlocal
TZ_UTC = tzutc() # UTC timezone
TZ_LOCAL = tzlocal() # Local timezone
datevalue = value #value I get from API I am using, which is datetime object.
# For some reason I don't get tzinfo filled).
datevalue = datevalue.replace(tzinfo=TZ_UTC) # Adding time zone info for UTC
datevalue = datevalue.astimezone(TZ_LOCAL) # Converting to local timezone
datevalue = datevalue.replace(tzinfo=None) # Removing tzinfo to correctly record local time to Excel
cell.value = datevalue
Excel itself has no concept of timezones and will always dates and times naively. In this context the only sane thing to do is to convert to UTC which is what openpyxl does. openpyxl.utils.datetime is the module to look at if you want to change this
I ended up using a combination of javascript & server-side processing:
At the client HTML I create an input for user's local timezone:
<input type="hidden" value="" name="tz" id="xls-tz"/>
and populate its value (using jQuery):
$("#xls-tz").val(new Date().getTimezoneOffset());
At the server, I parse the timezone offset & write to openpyxl accordingly:
tz_offs = int(request.GET.get("tz", "0"))
ws.cell(row=row, column=2, value=item.time - timedelta(minutes=tz_offs))
That comes IMO pretty close to what I needed.
Thanks Charlie for the hint about Excel not being TZ aware.
I'm using ReportLab in Django. I have a model with the following field:
time_stamp = models.DateTimeField(auto_now_add=True)
And my TIME_ZONE variable in settings.py is set to:
Africa/Johannesburg
I use a formset to populate this model. The time_stamp field saves correctly with the correct time zone, but when I place the time_stamp in my ReportLab pdf, the time zone is set to UTC.
For example:
time_stamp in the saved model (as str(time_stamp)[:19] is:
2015-03-04 07:57:28
But time_stamp in pdf document (as str(time_stamp)[:19] is:
2015-03-04 05:57:28
Exactly 2 hours earlier (Africa/Johannesburg is UTC + 2hours).
How can I set the time zone for ReportLab? Should it be specified in settings.py or in views.py while generating the pdf? If there is no solution, how do I add 2 hours to the time_stamp?
Some answers suggested changing auto_now_add=True with default=datetime.datetime.now(), but this creates a warning while migrating the database (Naive expression used).
I'm not a user of Reportlab but in general I don't think setting USE_TZ=False is the right approach to solve your problem. Set it back to True and instead of truncating your time stamp yourself like:
str(time_stamp)[:19]
You should try applying Django's date template filter in your template, e.g.:
{{ time_stamp|date:"SHORT_DATETIME_FORMAT" }}
It can be confusing how Django is handling timezones. But it's best practice to save timestamps in your database in UTC. You may want to refer to Django's timezone FAQ:
https://docs.djangoproject.com/en/dev/topics/i18n/timezones/#time-zones-faq
I want to enter date and time in my admin site with
date = models.DateTimeField()
But I dont want to have the seconds in my view. Is it possible to display the time like this:
10:45 instead of 10:45:00 ?
Yes you can:
https://docs.djangoproject.com/en/dev/ref/forms/fields/#datetimefield
input_formats
A list of formats used to attempt to convert a string to a valid datetime.datetime object.
If no input_formats argument is provided, the default input formats are:
Thats if you want to save as well with no seconds, If you only want to change how its displayed in your templates your can use the date template filter:
https://docs.djangoproject.com/en/1.6/ref/templates/builtins/#date
I have a field which will represent the start time of an event and I am using the Django DateTimeField for this.
This field is mandatory but sometimes the users will only know the start date and not the time.
Is there anyway to make the time part optional and keep the date part mandatory?
Maybe you should try to separate date from time. There are DateField and TimeField for that.
Example for use at the views or models:
You can use function strptime to show the datetime field any formats.
from datetime import datetime
datetime.now().strftime('%Y-%m-%d')
# print string '2013-06-25'
Example for use at the templates:
you can use templatetag date
{{ datetime_field|date:"Y-m-d" }}