```
import time
import os

T = int(input("Enter desired time for the timer - "))
t = time.localtime(time.time())

def Timer():
    while ((t.tm_sec) != T+(t.tm_sec)):
        return t
    else:
        os.system("start C:/Users/Public/Music/Sample Music")

Timer()

```

I have been working on this timer and can't get it to work. Basically, I want it to play the song I have in my system when the time is up. I have been trying to write this program and I can't understand why my code doesn't run the way I want it to. Could someone please point out if there's a mistake in it?