make clear obs_window_seconds and obs_window_days are unsupported

[nancycollins]

Description

both filter and perfect_model_obs have obs_window_days and obs_window_seconds in their namelists. these are for future use and are currently unsupported. update the docs to be more clear about this and update the code to print out a warning message if they are changed to be >= 0.

also check both the days and seconds values for obs_window_xxx and also init_time_xxx. if either are >= 0, call set_time(). that will catch and print a fatal error if one is set and the other is left at -1. the old code only tested days, so if someone set seconds >= 0 but left days negative the init time would have been set to 0, 0 and the namelist values wouldn't have been used without any message.

Fixes issue

#520

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update

Documentation changes needed?

• My change requires a change to the documentation.
  • I have updated the documentation accordingly.

Tests

I ran Lorenz 96 pmo and filter with various combinations of values in the namelist for both init_time_xxx and obs_window_xxx and it gave me the results i expected.

Checklist for merging

• Updated changelog entry
• Documentation updated
• Update conf.py

Checklist for release

• Merge into main
• Create release from the main branch with appropriate tag
• Delete feature-branch

Testing Datasets

• Dataset needed for testing available upon request
• Dataset download instructions included
• No dataset needed

[hkershaw-brown]

closing,

• the original user reporting problems was getting a hang because of this bug bug: dart doesn't catch 0 size model advance windows (hangs for subroutine callable models) #535

if you need to get the branch:
https://github.com/hkershaw-brown/DART/tree/obs_window_fix