30 minutes = 1,800 seconds:
1800 / 0.524295 = 3433
1 hour = 3,600 seconds:
3600 / 0.524295 = 6866
1.5 hours = 10299
2 hours = 13732
And maybe it's somewhere else in the program that wasn't posted, but ..
It looks like you are adjusting the value in delayset according to the buttons.
Then comparing the delay time against delaystop in the handler.
Oh, and delaystop is both a variable and the Label to the Interrupt handler.
<br>
hth,
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