[pazos]

But I think your issue has nothing to do with sysclock.

Pocketbooks sleep cpu 2 seconds after an input event happens (touch or button presses). When the cpu is sleeping there's no way for programs to run code on it. Pressing again the screen or a button wakes the cpu.

If the minute changes in the time frame your device is awake you'll see the clock updating. If the cpu is sleeping you won't. IIRC there's a setting somewhere to tweak specific Pocketbook suspend times. If you really need a 100% accurate minute counter then you'll need to make sure your device won't sleep within 60 seconds since the last input event.

Edit: in case isn't super obvious. This will drain your battery way faster