Minutes? Seconds? Why not just do

perl -e 'use Time::Local;sleep(timelocal((0,45,8,19,8,102))-time);prin
+t "\a" while sleep 1'
[download]

This will at least save some CPU time while still doing something you should better do with crond, atd, or smth. similar on Win32 Plattforms.

lg,
daniel