[BUG] Claude doesn't know what month it is

Summary: Claude seems to know what day and year it is, but every month is January. This happens consistently in all cases where Claude applies a date to a file or names a branch, etc.

Environment

• Platform (select one):
• [ ] Anthropic API
• [ ] AWS Bedrock
• [ ] Google Vertex AI
• [ ] Other: <!-- specify -->
• Claude CLI version: 1.0.68
• Operating System: MacOS 15.5
• Terminal: zsh

Bug Description

Steps to Reproduce

1. Ask Claude "Write a doc with the title file-<today's date>-update.md and write a 1-sentence summary of your work today?

Result:

Expected Behavior

Claude names the file "file-2925-08-05-update.md" (today is August 5 not Jan 5)

Actual Behavior

Claude names the file "file-2925-01-05-update.md" (today is August 5 not Jan 5)

Additional Context

This happens 100% of the time Claude names a branch, writes a file, etc.