The button shown in the image to disable alarms for 12 hours doesn’t work. I think it works sometimes with some events, but it definitely doesn’t work with Blooming Mokokos event.
And since limited time event alarms have never been automatically disabled upon claiming rewards for that day, this is the only option for not seeing them pop up when you don’t need them. I also think that maybe there should be a shorter duration option than just 12 hours. What if someone plays late at night and disables alarms like so and then plays the next morning? Alarms will still be disabled since 12 hours may have not passed. Could have either for current session or 4-6 hours.