Recovery PR for #16173 after the fork branch was accidentally reset
during rewrite-cleanup.
Cherry-picked onto current `main`:
- fix(common/time_utils): correct fallback timestamp and ISO-8601
normalization
- fix(common/time_utils): preserve zero timestamps and mark regression
tests
- test(common/time_utils): make fallback assertions deterministic
Supersedes closed#16173 — same branch
`Harsh23Kashyap/fix/time-utils-edgecases`, rebuilt per @yuzhichang
recovery steps in
https://github.com/infiniflow/ragflow/pull/16173#issuecomment-4829663835
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Co-authored-by: Harsh Kashyap <harshkashyap@Harshs-MacBook-Pro.local>
Co-authored-by: Cursor <cursoragent@cursor.com>
## Summary
- Replace hardcoded CST (UTC+8) expected values in `test_time_utils.py`
with dynamically computed local-time expectations using
`time.localtime()` and `time.mktime()`
- Tests previously failed in any timezone other than UTC+8; they now
pass regardless of the system's local timezone
## Test plan
- [x] `uv run pytest test/unit_test/ -v` — 317 passed, 25 skipped
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-authored-by: Jim Smith <jhsmith0@me.com>
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
### What problem does this PR solve?
- Add time utilities and unit tests
### Type of change
- [x] Refactoring
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Signed-off-by: Jin Hai <haijin.chn@gmail.com>
