@staticmethod
def date_from_str(ts):
    return pytz.utc.localize(datetime.datetime.strptime(ts, '%Y-%m-%dT%H:%M:%S.%fZ'))
@staticmethod
def date_from_str(ts):
    return pytz.utc.localize(datetime.datetime.strptime(ts, '%Y-%m-%dT%H:%M:%S.%fZ'))