This is a functional stopwatch functioned by command blocks and uses structure blocks. Works in 1.21.
Features:-
1) Can work in real time.
2)You can warp time around from 1 and 10 seconds, minutes and hours. When it reaches 59:59:59, it resets itself back to 00:00:00.
Select version for changelog:
Changelog
# Updated description
Now supports version 1.21.