OT: Several commenters have mentioned both their oven clocks and microwave clocks getting out of sync. I'm curious as to why people set both of these clocks in the first place.

The microwaves and ovens I've seen do not actually require you to set the clock. None of their cooking features and functionality depends on it. It's just a convenience feature. I doubt that most people actually need two clocks in the kitchen, so why not just set one of them (or neither if you don't need a kitchen clock at all)?

Lots of ovens and microwaves don't allow you to disable the clock, so the alternative to setting them is to have them run out-of-sync, which is much more irritating than having to set them.

Ah...I'd forgotten about the ones that always show the time regardless of whether or not it has been set. I can see how that would get annoying.

I guess I've been lucky in that all the microwaves I've had over the last couple of decades, and the ones we had at work, do not show the time unless you've set it. My current one, which has 7 segment LEDs for the time digits, blanks all the digits, leaving just the colons. My prior one showed "--:--" if time was not set. The one before that had a graphical display and just showed blank where the time would normally go.

Mine has two alternatives: Clock or blinking red light. I choose the clock...

I can give you a personal counter-example: my oven requires the time to be set to run - without it, neither the fan nor any of the two heating elements turns on.

It's an old Bosch HBN202S

I have in my kitchen + living-room one clock based on NTP on a dashboard, one on a WiFi radio and one on the oven.

Depending on where I am I see one of them so all must be synchronized to the millisecond so that children are not late to school (school is nearby, which exponentially raises the risk of them being late because it is just "4 minutes" away).

This is one of the scientific uses of such multiple clocks.

There was this great design for a microwave that a UX designer proposed. One button for +30 seconds, no clock, and a door handle. That's it. Everything else is superfluous.

On most microwaves I encountered one can just press the start button and it will do just that: Start with a 30s countdown and pressing it again will add 30s.

As a person who uses a microwave a lot this sounds terrible, I could live with 30s resolution, but not having adjustable power level would not be acceptable. Cooking anything on 100% power is just a recipe for uneven heating.

Based on the other commenter maybe two buttons: start/+30 seconds and power level in 25% increments.

I just got rid of a GE microwave which required me to set both the time and date before heating food after a power outage. I never did figure out what the date was for since it was never displayed and the clock did not automatically adjust for daylight savings time.

On top of that it had a dedicated button for toggling between AM and PM when setting the clock, which served no purpose whatsoever after that point. I wish I knew what the designer was thinking when they came up with that.

Literally because it annoys me more having it not set properly