[FEATURE] Expose message timestamps from Claude Code CLI to Claude for elapsed time calculations

Preflight Checklist

• [x] I have searched existing requests and this feature hasn't been requested yet
• [x] This is a single feature request (not multiple features)

I previously created same ticket and it was closed without any analysis or justification. So creating a new one: https://github.com/anthropics/claude-code/issues/18582

Problem Statement

Claude is telling me he cannot compute elapsed time for a particular task I requested to do because he does not count with the timestamps on my side.

In other words:

Currently, Claude cannot see message-level timestamps in the conversation context
This prevents calculating real wall-clock time elapsed during a session
Use case: Understanding human time cost vs computational token cost for tasks
Request: Include timestamp metadata with each message in the conversation context passed to Claude

Proposed Solution

Possible solution / request could cover something like:

Display timestamps in the CLI output so users can see when each message was sent
Expose timestamps to Claude in the conversation context for time-based analysis
Use cases:

• Users tracking how long tasks actually take
• Claude calculating real elapsed time for efficiency analysis
• Performance metrics and productivity tracking

Alternative Solutions

_No response_

Priority

Medium - Would be very helpful

Feature Category

CLI commands and flags

Use Case Example

_No response_

Additional Context

_No response_