Script to set the time on the alpha clock five over serial

alphaclockfive_settime.py

#!/usr/bin/env python3

import datetime, serial, sys

if len(sys.argv) != 2:
    print(f'''Usage: {sys.argv[0]} <serial port>\n
This may reset the clock when opening the serial port.
example: {sys.argv[0]} /dev/ttyUSB0
will set the time on an Alpha Clock Five connected to /dev/ttyUSB0''')
    exit(1)

# figure out our current offset from UTC
# Using the current Unix timestamp for UTC, we find the time of UTC and of
# our local time. Using the difference in these times, we get our current
# timezone's offset.
# We use the current time (instead of 1 Jan 1970) for finding this offset,
# because DST varies with time.
# `import time; time.timezone` does not work because it ignores DST.
timestamp = datetime.datetime.now().timestamp()
utc_time = datetime.datetime.utcfromtimestamp(timestamp)
local_time = datetime.datetime.fromtimestamp(timestamp)
local_time_utc_offset = local_time - utc_time

ser = serial.Serial(sys.argv[1], 19200)

local_timestamp = (datetime.datetime.now() + local_time_utc_offset).timestamp()
ser.write(b'\xffST' + bytes(str(int(local_timestamp)), 'ascii'))
ser.close()