営業時間重複チェック

How to use

1. Click "Add Office" and select the time zone of each office.
2. Set the start and end of their working hours.
3. The tool shows which UTC hours all offices are simultaneously open (green).

Related time tools

• World Meeting Finder
• World Clock
• Business Days Calculator
• Public Holidays by Country

よくある質問

Is the business hours overlap tool free?

Yes, completely free with no signup and no usage limits.

Does my data leave my device?

No. All time zone math runs in your browser using the Intl API. Nothing is sent to any server.

Does it work on mobile?

Yes. The tool is mobile-first and works on iPhone Safari and Android Chrome.