def start_of_local_day(dt_or_d: Union[(dt.date, dt.datetime, None)]=None) -> dt.datetime:
    'Return local datetime object of start of day from date or datetime.'
    if (dt_or_d is None):
        date: dt.date = now().date()
    elif isinstance(dt_or_d, dt.datetime):
        date = dt_or_d.date()
    return DEFAULT_TIME_ZONE.localize(dt.datetime.combine(date, dt.time()))
Return local datetime object of start of day from date or datetime.
def start_of_local_day(dt_or_d: Union[(dt.date, dt.datetime, None)]=None) -> dt.datetime:
    
    if (dt_or_d is None):
        date: dt.date = now().date()
    elif isinstance(dt_or_d, dt.datetime):
        date = dt_or_d.date()
    return DEFAULT_TIME_ZONE.localize(dt.datetime.combine(date, dt.time()))