Inconsistent output dates between calev-core and systemd cli

[Sheryv]

Value of next elapse calculated by this library is different from the output of systemd-analyze calendar command for the same input values. Example:

• systemd

$ systemd-analyze calendar --iterations=1 "*-2-* 10:00:00"
  Original form: *-2-* 10:00:00
Normalized form: *-02-* 10:00:00
    Next elapse: Sat 2025-02-01 10:00:00 CET
       (in UTC): Sat 2025-02-01 09:00:00 UTC
       From now: 10 months 13 days left

$ date
Wed 20 Mar 2024 10:01:36 AM CET

• main method from calev-core

$ sbt core/run --ref "2024-03-20T10:01:00" "*-2-* 10:00:00"
Normalized:  *-02-* 10:00:00
Reference:   2024-03-20T10:01
Next Elapses:
- 2025-02-21T10:00

systemd returns 2025-02-01 and calev: 2025-02-21. Is this difference intentional or is it a bug?

[eikek]

This is a bug, 2025-02-21 doesn't make sense I believe. There are some tests defined in this file - if possible, would you mind adding a failing one? Of course, should you have time and energy to fix it, even better 😏

[Sheryv]

I took a quick look at the parser and I have no idea how to fix it