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.