def METHOD_NAME(local_tz):
    naive_dt = datetime(2022, 3, 27)
    aware_dt = local_tz.localize(naive_dt)
    utc_dt = aware_dt.astimezone(pytz.utc)
    naive_previous_dt = datetime(2022, 3, 26)
    aware_previous_dt = local_tz.localize(naive_previous_dt)
    assert start_of_previous_day(aware_dt) == aware_previous_dt
    assert start_of_previous_day(utc_dt) == aware_previous_dt