FIX: expand time slice selection for datetime64

[nocollier]

No description provided.

[codecov]

Codecov Report

Attention: Patch coverage is 11.11111% with 8 lines in your changes missing coverage. Please review.

Project coverage is 69.28%. Comparing base (25dbcfe) to head (56230cc).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
ilamb3/compare.py	11.11%	8 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #15      +/-   ##
==========================================
- Coverage   69.59%   69.28%   -0.31%     
==========================================
  Files          16       16              
  Lines        1253     1260       +7     
==========================================
+ Hits          872      873       +1     
- Misses        381      387       +6     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.