I was getting the buzzer at 59 minutes past the hour, not exactly on the hour. This changes to buzzing at exactly HOUR:00:00. Tested this locally.
After thinking about this, I think it is more intuitive that this would only apply when in setting mode.
Added option to reset to the default timer value when in waiting mode and on long press of alarm. This was useful to me as I sometimes accidentally increase the timer value and then would need to loop around to get back to the default value.
David KeckandGitHub