Time handicap in clock tool

[Mauritz8]

closes #628

[veloce]

Hi! Thanks for the PR. Can you please:

• resolve conflicts and rebase on last main branch
• post a screen recording showing the new feature?

[Mauritz8]

Screencast from 2024-06-06 19:46:10.webm

If you think that something should be changed, just let me know.