add option to fits reader to open L1 products also in UTC >L1 UTC per default (via keyword in header)

[nicHoch]

add keyword: get_timeformat_from_TIMESYS to Product(path) method.
If set time and timedel column in data table are converted to timesystem provided in the TIMESYS header keyword.

some products properties like utc_timerange, min_exposure ... might do autoconversions based on the internal timesystem but it should be avoided to open L1 files in UTC for processing them further.

Use get_timeformat_from_TIMESYS=True only for reading excess to L1 data, read/write/combing might lead to timing accuracy issues

[codecov-commenter]

Codecov Report

❌ Patch coverage is 81.48148% with 10 lines in your changes missing coverage. Please review.
✅ Project coverage is 67.04%. Comparing base (3ae9671) to head (9b9c9dc).
⚠️ Report is 11 commits behind head on master.

Files with missing lines	Patch %	Lines
stixcore/products/product.py	86.95%	6 Missing ⚠️
stixcore/products/level1/quicklookL1.py	20.00%	4 Missing ⚠️

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HEAD has 1 upload less than BASE

Flag	BASE (3ae9671)	HEAD (9b9c9dc)
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Additional details and impacted files

@@            Coverage Diff             @@
##           master     #447      +/-   ##
==========================================
- Coverage   72.23%   67.04%   -5.19%     
==========================================
  Files          78       76       -2     
  Lines        8085     8136      +51     
==========================================
- Hits         5840     5455     -385     
- Misses       2245     2681     +436     

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[samaloney]

I'm not sure allowing operations in different time systems is a good idea. A product should either have time in OBT or UTC and the conversion should only be done once in the from_level0 or similar methods?

All products (>L0) will always have obt_timerange from products will have an utc_timerange but only if the time sys in header is UTC and not sure supporting on the fly conversion is a good idea because the spice kernel dependence.

This aren't blocker just thoughts

[nicHoch]

i agree that it is not ideal to provide some of the on the fly conversions. The auto converting most of the time (and if proper used never) will not happen as our process steps will do this explicit.

In general this L1 product could have state depended time systems and i think it would be bad experience if the properties will raise an exception if used

[Copilot]

Pull request overview

This PR adds an opt-in reader behavior to interpret FITS time columns using the TIMESYS/DATE-OBS header context (via get_timeformat_from_TIMESYS=True) so L1 products can be opened in UTC when needed, while keeping SCET/OBT as the default for processing workflows.

Changes:

• Add get_timeformat_from_TIMESYS option to Product(path) reading logic to choose UTC vs OBT-based offsets when reconstructing time/timedel.
• Update time-range properties and product combination logic to handle non-SCETime internal time formats.
• Rename exposure to min_exposure across FITS header generation and tests.

Reviewed changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
stixcore/util/scripts/end2end_testing.py	Adds local debug code in __main__ (currently breaks script execution).
stixcore/products/tests/test_factory.py	Adds test coverage for reading time formats (SCET vs UTC).
stixcore/products/product.py	Implements time-format selection from headers; updates timerange logic; renames exposure API; introduces UTC tz-aware constant.
stixcore/products/level3/flarelistproduct.py	Adds warning log when SCET is approximated from UTC using SPICE.
stixcore/products/level3/flarelist.py	Adds warning logs; renames exposure to min_exposure.
stixcore/processing/tests/test_publish.py	Updates tests to use min_exposure.
stixcore/processing/tests/test_end2end.py	Alters pytest markers for the end-to-end identical test.
stixcore/io/product_processors/tests/test_processors.py	Updates tests to use min_exposure and expect XPOSURE from it.
stixcore/io/product_processors/fits/processors.py	Writes XPOSURE from min_exposure; minor refactor of scet_timerange usage.

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[samaloney]

Seems ok, one test marker commented out?

[samaloney]

?