There is an adjustment screw on the back of the clock, but you should be careful with it, as even a small adjustment will make a difference. On top of that, it takes time to adjust this, as you should let it run 24h between any adjustments. Just be patient, and you should get there.
Oh, and let me add, you're lucky who has a clock that works. I have 3 Type 3 clocks here, none of them are working
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