Take care of the minutes, for the hours will take care of themselves.
Lord Chesterfield
While there are a lot of countdown timer and Pomodoro apps, I was looking for a simple solution. Something that could play a simple audio file, not the aversive macOS alarm.
ChatGPT did create this timer (see HTML file here). Note that it needs an audio file (gong.m4a), without it, it throws an error once the countdown is done («but the browser blocked sound»). I used a simple gong sound from YouTube which is not included due to copyright. You can adapt the HTML file to add other durations or sound file names.
No warranty, but you should be able to save the html to your computer, add a gong.m4a alert sound file to the same directory, and it should work.
Still impressive what AI can do.