[Answer]-Django Migrate – change charfield to datetimefield

Django’s approach to timezone handling is to convert all datetimes to UTC and then store them in the database without any timezone information. Apparently your CharFields include a timezone field.

One approach would be to edit the migrations file produced by makemigrations and insert a RunPython command as the first operation. Use that to convert your CharFields to a string UTC version without timezones. That might look something like this:

from django.utils.dateparse import parse_datetime
from django.utils import timezone

days_aware = parse_datetime(days)
days_utc = days_aware.astimezone(timezone.utc)
days_naive = days_utc.replace(tzinfo=None)
days = str(days_naive)

Alternatively, instead of changing the string representation, you could instead create the DateTimeField as a new field (say days_dt); do a RunPython data migration where you convert the string to a datetime (days_dt = parse_datetime(days)); delete the days field; and rename days_dt to days. That would also work and would leave Django in charge of representing datetimes at the database level.