I'm assuming you need to unplug the battery to set the "true" time? Else you might be adjusting the "I'm in my +10 minutes phase" (for early clock, f.ex), turn

I'm assuming you need to unplug the battery to set the "true" time? Else you might be adjusting the "I'm in my +10 minutes phase" (for early clock, f.ex), turning it into late clock. (?)