Forty-one minutes is a prime stretch for a single piece of work you have been fragmenting all week. Close the extra tabs first. Forty-one minutes with a chat window open is not forty-one minutes.
The alarm should mean stop, even if the sentence is unfinished. Mark the cursor and leave. Press space to start or pause, R to reset, and F for fullscreen. The screen can stay awake after you start, using the wake lock your browser allows. Pick the alarm before you begin. A bell, a chime, a beep, or a short digital pulse all come from the Web Audio API, so there is no sound file to wait on.
This page is the 41 minutes countdown and nothing else is running underneath it. Related lengths are linked under the guide if you want a neighbor, and the timer itself stays above the fold.
Questions
How do I run a 41 minutes timer on a projector?
Press start, then F or the fullscreen button. Classroom mode hides the writing so the digits fill the wall. The alarm should mean stop, even if the sentence is unfinished. Mark the cursor and leave.
What is 41 minutes actually good for?
Forty-one minutes is a prime stretch for a single piece of work you have been fragmenting all week.
Will the countdown drift if I switch tabs?
No. The end is a timestamp. The display is the gap between that timestamp and now, so a background tab does not lose seconds the way a ticking counter would.