Fashionably Late by Fenil Dedhia

Being fashionably late is a good thing for email, too. If you work across time zones and keep doing the mental math on when to hit send, this free add-on helps you schedule emails in Gmail at the right time, automatically.

What you get:
✓ Scheduling suggestions in your recipient's local timezone, so your message arrives when they're at their desk instead of buried overnight, learned once and remembered
✓ A friendly working-hours check before you send, so late-night emails don't go out by accident
✓ Built right into Gmail's native Schedule send, with no new interface to learn
✓ Your scheduled emails stay in Gmail's normal Scheduled folder

Your privacy comes first:
• Everything runs on your device. There is no Fashionably Late server and no account to create.
• No Google sign-in and no Gmail API access. It reads only the recipients in your compose window to suggest timezones, never your message content.
• No tracking, no analytics, no telemetry. Nothing ever leaves your browser.
• View, export, or delete all your data anytime from Settings.

Fashionably Late is open source (Apache 2.0).