This PR adds support for delta time syntax (-1d, -1w, -1mo) to the --start-date and --end-date flags in the gh aw logs command, making it much easier to filter workflow runs using relative dates. Additionally, it improves precision across the entire time delta system by always using precise date calculations.

New Delta Time Syntax

Users can now specify relative dates using intuitive syntax:

# Get runs from the last week
gh aw logs --start-date -1w

# Get runs up to yesterday  
gh aw logs --end-date -1d

# Get runs from the last month
gh aw logs --start-date -1mo

# Complex combinations work too
gh aw logs --start-date -2w3d --end-date -1d

Supported Time Units

• Days: -1d, -7d
• Weeks: -1w, -4w
• Months: -1mo, -6mo
• Hours/Minutes: -12h, -30m (for sub-day precision)
• Combinations: -1mo2w3d, -2w5d12h

Always-Precise Date Calculations

Improved precision across the entire time delta system by eliminating conditional calculation logic:

• Before: Used AddDate() only when months/weeks were present, fell back to simple duration arithmetic otherwise
• After: Always uses AddDate() for months, weeks, and days for maximum precision in all scenarios
• Benefits: Proper handling of varying month lengths, leap years, and daylight saving time transitions for all time calculations
• Applies to: Both the new gh aw logs command and existing workflow stop-time field functionality

For example, adding 1 day on a daylight saving boundary:

• Old method: Simple 24-hour duration (could be off during DST transitions)
• New method: Uses AddDate() which properly handles calendar day boundaries

Implementation Details

The implementation extends the existing time delta parsing infrastructure from the compiler's stop-time field functionality:

1. Extended TimeDelta struct to support weeks and months
2. Added new parsing functions for negative deltas (going backwards in time)
3. Created ResolveRelativeDate function that resolves relative dates to absolute YYYY-MM-DD format for GitHub CLI
4. Updated logs command to parse and resolve delta dates before passing to GitHub CLI
5. Enhanced help text with examples of the new syntax
6. Always use precise calculations in both ResolveRelativeDate and resolveStopTime functions by eliminating conditional logic
7. Updated documentation in instructions.md to document the new logs command functionality

Backward Compatibility

All existing functionality remains unchanged:

• Absolute dates like 2024-01-01 continue to work exactly as before
• All existing CLI flags and behavior preserved
• The change is purely additive

Example Usage

# Traditional absolute dates (still work)
gh aw logs --start-date 2024-01-01 --end-date 2024-01-31

# New relative dates  
gh aw logs --start-date -1w          # Last week's runs
gh aw logs --end-date -1d            # Up to yesterday
gh aw logs --start-date -1mo         # Last month's runs
gh aw logs --start-date -2w3d        # 2 weeks 3 days ago

# Works for workflow stop-time too (now with always-precise calculation)
stop-time: +1mo  # Exactly one month from compilation

The command automatically resolves these relative dates to absolute dates before calling the GitHub CLI, ensuring full compatibility with GitHub's API.

Testing

Added comprehensive test coverage with 95+ new test cases covering:

• All supported time units (days, weeks, months, hours, minutes)
• Negative and positive deltas
• Complex combinations
• Edge cases and error handling
• Date resolution accuracy
• Always-precise calculations in both ResolveRelativeDate and resolveStopTime

Fixes #111.

💡 You can make Copilot smarter by setting up custom instructions, customizing its development environment and configuring Model Context Protocol (MCP) servers. Learn more Copilot coding agent tips in the docs.