You can use the datediff function for this.
It can go in the timer function you have from the last post so it is tested every time the time changes.
if (DateDiff("s", YourAlarmDateTime, Now()) > 0) then
msgbox("Ring Ring Ring.....")
'Now that the time is after the alarm time you must either disable the alarm code or change the alarm time.
'Because it will execute every time the timer function is run.
'Add 24 hours to alarm
YourAlarmDateTime= DateAdd("h", 24, YourAlarmDateTime)
They say, best men are moulded out of faults,
And, for the most, become much more the better
For being a little bad.