Fix date issues, mobile and desktop

[amponce]

Are you removing, renaming or moving a folder in this PR?

• No, I'm not changing any folders (skip to TeamSites and delete the rest of this section)

Summary

• We originally ran into trouble storing partial date strings like “YYYY-MM-XX,” which led to validation failures and off-by-one-year issues on some devices. To fix this, we switched to consistently storing “YYYY-MM” and converting to a valid “YYYY-MM-01” format for validation, removing the time zone confusion. We also updated our helper function (monthYearFormatter) to gracefully handle legacy formats, ensuring a consistent display of “MM/yyyy” across the fsr

Related issue(s)

• Link to ticket created in va.gov-team repo
  [FSR] - Fix Employment Work Date Validation for Mobile va.gov-team#99274

Testing done

• Manual verification, visual verifcaiton of final pdf submissions in both desktop and mobile, see attached

Screenshots

Note: This field is mandatory for UI changes (non-component work should NOT have screenshots).

Mobile

What areas of the site does it impact?

(Describe what parts of the site are impacted if code touched other areas)

Acceptance criteria

Quality Assurance & Testing

• I fixed | updated | added cypress tests and integration tests for each feature (if applicable).
• No sensitive information (i.e. PII/credentials/internal URLs/etc.) is captured in logging, hardcoded, or specs
• Linting warnings have been addressed
• Screenshot of the developed feature is added
• Accessibility testing has been performed

Error Handling

• Browser console contains no warnings or errors.

[amponce]

Test form submissions show date is working as expected

VA Form 5655 - Submitted (11).pdf
VA Form 5655 - Submitted (12).pdf

[OptionSelect]

LGTM! 🚀

[Dr-Pongo]

LGTM! 🚀