t1_unpacked = struct.unpack('<q', t1)[0]
t1_seconds = t1_unpacked / 52428800
t1_us = int(round(t1_unpacked % 52428800 / 52.4288, 0))
GPS_EPOCH + datetime.timedelta(seconds=t1_seconds, microseconds=t1_us)
Covert binary 64-bit timestamp offset from the GPS epoch to python datetime object