[BUG] Claude unexpectedly modify creation date of a file on macOS

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

I used Claude to edit a bunch of markdown notes, and I noted that this broke some workflow I have based on the file creation time. So I checked the file's stats:

stat -f "Access (atime): %Sa%nModify (mtime): %Sm%nChange (ctime): %Sc%nBirth  (Btime): %SB" my_note.md
Access (atime): Oct  2 15:45:34 2025
Modify (mtime): Oct  2 15:37:10 2025
Change (ctime): Oct  2 15:45:33 2025
Birth  (Btime): Oct  2 15:37:10 2025

What Should Happen?

I expected that Claude editing a file changed the Change/Modify/Access timestamps, not the creation time.

Error Messages/Logs

Steps to Reproduce

1. Create a file. (e.g., a markdown note file)
2. After some time, ask Calude to change something in the file (e.g., add some data)
3. Check the stats, and check that the creation time has been moved to the timestamp of the modification.

Claude Model

Sonnet (default)

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.0.5

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_