Greptile Summary

This PR adds a Day of week line to the system prompt's "Current Date & Time" section when userTime is available. The implementation is sound:

• extractWeekdayFromUserTime uses a simple regex to parse the leading day name from userTime, correctly extracting the weekday from the expected input format.
• buildTimeSection conditionally spreads the Day of week: <weekday> line using a clean, non-breaking pattern.
• Tests cover 12-hour, 24-hour, and timezone-only cases and properly assert that the full date/time string is not injected, preserving the cache-stability invariant.
• The tradeoff between cache stability and scheduling accuracy is well-documented in comments and the PR description.

Confidence Score: 5/5

• Safe to merge. Changes are minimal, well-tested, and non-breaking.
• The implementation is correct and complete. The new function cleanly parses weekday from the expected input format, the integration is non-breaking, and the test suite covers all relevant cases including the important cache-stability invariant. No files require special attention.
• No files require special attention.

_{Last reviewed commit: 4a32ea0}

Hi Sriram thanks, this is very fair feedback.

You’re right on all three points:

Layering / architecture:
I agree this should follow the documented direction from #3658 (message-level timestamp context) unless maintainers explicitly decide otherwise.

Cache behavior:
Also agreed that weekday still introduces predictable daily prompt churn. It’s much smaller than full datetime churn, but it still breaks strict prompt stability.

Comment change:
Good callout. That comment edit effectively changed architectural intent without explicit consensus.

Given this, I’m happy to rework the contribution in one of these ways (maintainer preference):

A) Close this PR and open a new one that adds/improves message-level weekday/timestamp injection, or
B) Keep system prompt unchanged by default and gate weekday behind an explicit opt-in config flag (default off), with clear docs.
I can update quickly once i receive confirmation on preferred direction.