Python Alarm Clock

#!/usr/bin/python

import time
import subprocess
import sys
alarmhour = int(raw_input("Please enter the hour. (24h): "))
alarmmin = int(raw_input("Please enter the minute. (01-59): "))

while True:
	mytime = list(time.localtime())
	hour = mytime[3]
	minute = mytime[4]
	time.sleep(30)
	if hour == alarmhour and minute == alarmmin:
		subprocess.call('mplayer -loop 9 ring.wav', shell=True)
		sys.exit()