Daylight Saving Time broke Claude Desktop on Saturday night.
Users with scheduled tasks in Claude Cowork or Claude Code found their apps stuck in an infinite loop during the March 8 clock-forward. The root cause: when the app tried to find tasks scheduled during the "skipped" 2:00-3:00 AM hour, it couldn't resolve them and locked up. Classic edge case, and one that every developer who's dealt with time zones will recognize immediately.
Anthropic's team had the issue identified by 18:27 UTC and pushed a fix by 19:42 UTC - roughly two hours from first investigation to resolution. As an immediate mitigation, they disabled scheduled tasks for Cowork and Claude Code while working on the patch.
The fix is in version 1.1.5749, available now at claude.com/download. Anthropic also suggested temporarily switching to a non-DST timezone as a workaround, which is the kind of advice that's technically correct but practically useless for most people.
This is a minor incident in the grand scheme, but it highlights how scheduled task features in AI tools are still maturing. Claude's task scheduling launched relatively recently, and DST transitions are exactly the kind of real-world edge case that only surfaces once your feature hits enough users across enough time zones. Anthropic deserves credit for the fast turnaround, but the bug itself is a reminder that these AI assistants are being asked to do more system-level work - and that means more surface area for the mundane bugs that have plagued software forever.