i used filterset for my view in django like this :

class CalendarEventListFilter(filters.FilterSet):
    start_time = filters.DateTimeFilter(field_name='start_time', lookup_expr="gte")
    end_time = filters.DateTimeFilter(field_name='end_time', lookup_expr="lte")

    class Meta:
        model = CalendarEvents
        fields = ['start_time', 'end_time']

and this is my model :

class CalendarEvents(BaseTimestampModel, BaseOwnershipModel):

    EVENT_KINDS = [
        ('DANGER', _("Danger")),
        ('SUCCESS', _("Success")),
        ('WARNING', _("Warning")),
        ('INFO', _("Info")),
        ('NEUTRAL', _("Neutral")),
    
    ]

    kind=models.CharField(max_length=100 , choices=EVENT_KINDS)
    name = models.CharField(_('name'), max_length=150)
    start_time = models.DateTimeField(_('start time'))
    end_time = models.DateTimeField(_('end time'))
    reminder_time = models.DateTimeField(_('reminder time'))
    description = models.CharField(_('description'), max_length=255)

    
    class Meta:
        ordering = ['-id']
        verbose_name = _('calendar event')
        verbose_name_plural = _('calendar events')
        default_permissions = ()
        permissions = ()

    def __str__(self):
        return self.name

also this is my view :

class CalendarEventListView(ListAPIView):
    queryset = CalendarEvents.objects.all()
    serializer_class = CalendarEventListSerializer
    permission_classes = (IsAuthenticated,CanViewCalendarEvents)
    filter_backends = (filters.DjangoFilterBackend, SearchFilter, OrderingFilter)
    filterset_class = CalendarEventListFilter
    pagination_class = None 

the problem is that when i use api endpoint and send request with this format
api//calendar_events/?start_time=2020-01-01
it works . but when i use end_date like this
api//calendar_events/?start_time=2020-01-01&end_time=2021-01-02
it doesnt work .
also i checked my settings are :

TIME_ZONE = ‘UTC’

USE_I18N = True

USE_TZ = True

when i use
api//calendar_events/?end_time=2021-01-02 also not working !

tested database too !
tried getting objects from shell also no working !
tried postman too .
tried raw query directly from database too .