Django splitDateTime widget, no JS, using modern HTML for time and date selectors

MinimalSplitDateTimeMultiWidget.py

from datetime import datetime
from django.utils.timezone import make_aware
from django.forms import TextInput, MultiWidget, DateTimeField


# nightmare discussion here https://stackoverflow.com/questions/38601/using-django-time-date-widgets-in-custom-form
class MinimalSplitDateTimeMultiWidget(MultiWidget):

    def __init__(self, widgets=None, attrs=None):
        if widgets is None:
            if attrs is None:
                attrs = {}
            date_attrs = attrs.copy()
            time_attrs = attrs.copy()

            date_attrs['type'] = 'date'
            time_attrs['type'] = 'time'

            widgets = [
                TextInput(attrs=date_attrs),
                TextInput(attrs=time_attrs),
            ]
        super().__init__(widgets, attrs)

    # nabbing from https://docs.djangoproject.com/en/3.1/ref/forms/widgets/#django.forms.MultiWidget.decompress
    def decompress(self, value):
        if value:
            return [value.date(), value.strftime('%H:%M')]
        return [None, None]

    def value_from_datadict(self, data, files, name):
        date_str, time_str = super().value_from_datadict(data, files, name)
        # DateField expects a single string that it can parse into a date.

        if date_str == time_str == '':
            return None

        if time_str == '':
            time_str = '00:00'

        my_datetime = datetime.strptime(date_str + ' ' + time_str, "%Y-%m-%d %H:%M")
        # making timezone aware
        return make_aware(my_datetime)

I've replaced this solution with the shorter one posted by @spookylukey and it seems to work fine. So I don't think it has anything to do with Firefox.