Comment by jonathanlydall

I'm guessing you're being downvoted largely due to the "don't be snarky" rules.

You're right (by my maths too, which I only did now) about it being a discrepancy of 43.2 seconds per day, which as you say is quite high.

However, it is my understanding that most grid operators are actually very good about maintaining a 50Hz average over a day specifically for devices doing time keeping based their frequency, I've heard they intentionally run the generators faster or slower at certain points in the day in response to needing to get the average right over a day.

I used to have no issues with time drift on my microwave, only started in the last few years.