If this sounds like your week
Missed endings teach you to ignore the timer.
A gentle notification is easy to miss in headphones, calls, music, shared rooms, and busy desktops. If the end of a block matters, the cue has to be visible enough and audible enough for your setup.
Where tooling usually breaks
Your hardware decides what “loud” means.
Windows volume, app mixer levels, headphones, Bluetooth devices, and room noise all affect whether an alert lands. Any serious timer setup should be tested on the actual machine.