"/time set <timemarker>" is unable to decrease time

The bug

/time set <timemarker> command is unable to decrease time.

This makes /time set <timemarker> not working properly with non-looping (i.e. without period_ticks field) timelines.

Steps to reproduce

1. Install the attached datapack and rejoin the world. The datapack creates a paused world clock example:clock.

2. Set time to constant 0: /time of example:clock set 0.

3. Query time: /time of example:clock query time → 0 ✅

4. Set time to the marker of 1: /time of example:clock set example:one.

5. Query time → 1 ✅

6. Set time to the marker of 2: /time of example:clock set example:two.

7. Query time → 2 ✅

8. Set time to the marker of 1: /time of example:clock set example:one.

9. Query time → 2 ❌

Expected behavior

The outputs of (5) and (9) should be consistent.

Observed behavior

The output of (9) is not 1.