Handling Timezone-Sensitive Date Calculations in Django with PostgreSQL
I'm writing unit tests and Can someone help me understand I've encountered a strange issue with I've been struggling with this for a few days now and could really use some help... I'm working on a personal project and I'm trying to perform date calculations in my Django application that uses PostgreSQL as the database backend. My main concern is ensuring that the date and time values are correctly managed when users from different time zones interact with the application. I've encountered an scenario where the date calculations seem to be off when I compare dates stored in the database with the user's local time. For example, I have a model that stores an event's start time as follows: ```python from django.db import models class Event(models.Model): title = models.CharField(max_length=100) start_time = models.DateTimeField() ``` When I create an event with a start time like this: ```python from django.utils import timezone # This assumes the server is set to UTC event = Event(title='Meeting', start_time=timezone.now()) event.save() ``` Everything seems fine until I try to retrieve events for a user in a different timezone. My user is in EST, and I fetch events like this: ```python from django.utils import timezone # Get current time in user's timezone user_timezone = pytz.timezone('America/New_York') now = timezone.now().astimezone(user_timezone) # Attempt to filter events occurring today today_events = Event.objects.filter(start_time__date=now.date()) ``` However, when I run this, the query returns no events even if they should exist. I've confirmed that the start_time in the database is indeed in UTC, but it seems the comparison is failing. The behavior I'm seeing is that the events are not being found, even though I can print out the `start_time` from the database and it clearly shows the correct UTC value. I've tried using `timezone.localtime(event.start_time)` in my filter, but that doesn't seem to help either. I'm also passing the `USE_TZ = True` setting in my Django settings. What could I be doing wrong in handling the timezone when filtering events? Is there a best practice I should follow to ensure that Iām correctly comparing datetime objects in different time zones? Any ideas what could be causing this? Is there a simpler solution I'm overlooking? I recently upgraded to Python 3.11. Has anyone dealt with something similar?