[Someone]

If that isn't satire, how are you using the on-screen clock to do that?

Do you start staring at it at around 17:20 (or even earlier?) and wait for it to hit 17:28:15, or is your internal clock so good that you only have to start staring at it at 17:28:00?

Either way, why spend time staring at an on-screen clock if you also could spend that time walking to the train station, or even walking on the platform?

I would find some tool that allows me to set daily alarms at around 17:15 (as an early warning to finish whatever I am doing) and 17:28:15 (as a sign to leave now), so that I wouldn't have to waste time staring at that clock.

[neverminder]

It's not that hard once you're used to it. I just glance at the clock several times towards the end of work to know exactly when to wind things down and stand up from my chair at exactly 17:28:15. The optimal time was determined by observing elevator business patterns, crowd thickness downstairs and delay margins of train arriving at my stop.