Unhelpful error message for Deadline

[Huggenguggen]

When adding a new role with a deadline that is before the current date, the error message is not helpful for the user to realize their mistake.

The date is in the correct format but the restriction has not been met.

Suggestion: Have an error message for when a parameter's restrictions aren't met so as to make user's life easier

[nus-pe-bot]

Team's Response

Duplicate of #3272. Referring to error message in TechTrack for invalid dates entered.

The 'Original' Bug

[The team marked this bug as a duplicate of the following bug]

Error message for incorrect date format not specific enough

Steps to repro:

1. Edit a role to have a deadline that is in this format YYYYMMDD e.g. edit 6 d/20250228

Expected error message: The deadline should follow this format: YYYY-MM-DD

Actual: Deadline does not exist. Please key in a date that exists.

---

_{[original: nus-cs2103-AY2223S2/pe-interim#2604] [original labels: severity.Low type.FeatureFlaw]}

Their Response to the 'Original' Bug

[This is the team's response to the above 'original' bug]

Good Catch, we will accept this bug

Items for the Tester to Verify

:question: Issue duplicate status

Team chose to mark this issue as a duplicate of another issue (as explained in the Team's response above)

• [ ] I disagree

Reason for disagreement: [replace this with your explanation]

---

## :question: Issue type Team chose [`type.FeatureFlaw`] Originally [`type.FunctionalityBug`] - [x] I disagree **Reason for disagreement:** Going by the textbook,  The error message not really matching/being specific enough should be a functionality bug.

---