There was a clock on HN a while ago (which I cannot now find) - it has one mode in which the clock only updates itself every random number of seconds, or ticks

There was a clock on HN a while ago (which I cannot now find) - it has one mode in which the clock only updates itself every random number of seconds, or ticks at different times within each second, oor ticks according to a MIDI tune as well as it can while staying within 30 seconds of the real time. So, while you can just set your clock forward 30 seconds and be done with it, there are some variations that someone who likes thinking about this are worth playing with. [My favorite mode of the referenced clock, sets the clock randomly ahead between 1-5 min. Since you don't know how much your clock is off by, you have to assume your clock is on time, and that will give you an average 2.5 minutes to actually show up on time.]