Summary

The Validate-MarkdownFrontmatter.ps1 script should accept (YYYY-MM-dd) as a valid token for the ms.date field in template files, in addition to actual ISO 8601 dates.

Problem

Template files (e.g., ADR templates, documentation templates) use placeholder tokens like (YYYY-MM-dd) in the frontmatter to indicate where actual dates should be inserted when the template is used. Currently, the validation script only accepts dates matching the pattern ^\d{4}-\d{2}-\d{2}$, causing warnings for template files.

Current behavior:

Invalid date format in: docs/templates/adr-template-solutions.md. Expected YYYY-MM-DD (ISO 8601), got: (YYYY-MM-dd)

Proposed Solution

Update the date validation logic in Validate-MarkdownFrontmatter.ps1 to:

1. Accept (YYYY-MM-dd) as a valid placeholder token for template files
2. Optionally detect template files by path pattern (e.g., **/templates/**) or filename pattern (e.g., *-template*.md)

Suggested Implementation

Modify the date validation regex from:

if ($date -notmatch '^\d{4}-\d{2}-\d{2}$') {

To also accept the placeholder pattern:

if ($date -notmatch '^(\d{4}-\d{2}-\d{2}|\(YYYY-MM-dd\))$') {

Files Affected

• scripts/linting/Validate-MarkdownFrontmatter.ps1 - Lines 482-485 and 572-577

Acceptance Criteria

• (YYYY-MM-dd) is accepted as a valid date token
• Actual ISO 8601 dates (2025-12-05) continue to work
• Template files in **/templates/** directories pass validation
• No breaking changes to existing validation behavior