My bike speedometer is the worst for this. It has 3 buttons. Each one can be pressed short, medium (>3 seconds), or long (>5 seconds). Every action changes something on the display, but god knows what all the icons mean. Most actions are statefull, with a surprisingly deep menu structure. If you do the wrong thing, e.g. press long instead of medium, something surprising happens, and you're in hell finding the way back to the main menu and try again. Easy option is waiting 2 minutes until it returns by itself.<p>It has a gigaton of functions, but I only need 3: speed to not drive too fast, time to know if I'll arrive on time, km driven to know if I need maintenance. All other stuff in there is unused.<p>At this point, I've given up. In winter, I add an hour. I know the clock is 2 minutes off and I subtract them myself. If I have to spellunk in the dark dungeons of the menu structure again, I might accidentally drop a hammer on the thing.<p>Apart from that, it's a great speedometer. The worst is knowing I am the official techie and watch DST fixer for half my extended family, and no other clock has thwarted me so severely, ever...