Describe the bug
The late_submission_warning_messages.spec.js Cypress test has 4 failures on main. The tests expect a different number of late days than what the application returns. For example, the test expects "Your submission will be 4 day(s) late" but the application returns "Your submission will be 3 day(s) late."

Expected behavior
All 11 tests in late_submission_warning_messages.spec.js should pass on main. The late day counts in the application should match what the tests expect.

To Reproduce
Steps to reproduce the behavior:

1. Run the Cypress (Gradeable) CI suite on the current main branch
2. Observe 4 failures in late_submission_warning_messages.spec.js
3. Failing tests:
   "Confirmation for the first submission with 2 remaining late days and 1 extension"
   "Warning message for the second submission with 0 valid remaining late day"
   "Confirmation for the first submission with 2 remaining late days and 1 extension for teams"
   "Warning message for the second submission with one team member having 0 remaining late days"
4. See error : late day counts are off by one, likely due to date/time sensitivity

Configuration
CI environment (GitHub Actions, Ubuntu)
Browser: Chrome 146 (headless)

Screenshots
N/A — failures visible in CI logs.

Additional context
This appears to be a date/time sensitivity issue similar to the cascading failures seen in PR #12571 where date changes affected test behavior.

CI run showing the failure on main: https://github.com/Submitty/Submitty/actions/runs/23856035445