snoozed alarm are still running after shutdown/reboot 12 hours later

Hmm, that's true. As people nowadays suspend / resume their laptops often, alarms that are triggered too late shouldn't be ignored so easily though. One solution would be to ignore an alarm if it's triggered more than X hours too late. Maybe one hour..? I'm trying to think of any corner cases where such a static limit would be unfortunate... How is this problem handled by regular alarm clocks, I wonder?

How about having alarm-clock display a 1 minute pre-alarm warning timer, allowing the end-user to dismiss the alarm immediately after resuming from suspension/hibernation, before it actually goes off. So the end user wakes the machine from suspension/hibernation, and instead of being immediately greeted by a rather obnoxious and potentially unnecessary alarm, they greeted with a message asking whether they would like to skip todays alarm (still annoying, but less so than an unwanted noise at 09:30 in the office).

Also, maybe an tickbox as "Cancel snoozed alarms after suspension/hibernation" can be added to the preferences.

I am resurrecting an old thread, but this is because not only this is still at the same stage, but I found an additional bug to it.

I have a recurring alarm at night to remind me to leave work on time to pick-up my daughter at school (I can be quite involved in my work and forget about the clock...). Anyway, it also happens that I actually watch the clock and turn of my computer a bit before the alarm goes on. In that case, not only the alarm starts the next day when I turn on the computer, but if I turn it off it also cancels the alarm-to-come for that day, which is unexpected.

De-activating the recurring alarm and re-activating it right away allows to get everything back to normal, but this is a bit annoying...

I have created a new bug 1122500 for the problem with the daychange.

Please keep this bug about the alarm after reboot.

Could this be solved with a check-box with the alarm?

More than 3 years later now and it's still happening. I've recently turned to using this app instead of my phone when my phone is dead and am having this issue with resuming and having alarms go off way after the time I asked them to which is completely incorrect.
I think there should be no checks and no pre-checks other than "is it the time that you set it to go off at?" and if not, be silent. If you miss one, too bad, it wasn't turned on at that time so there's no way it should try again.

Also adding that this is also on schedule rather than snooze as OP said