World Clock Converter with AI Scheduling
See live clocks for every participant, compare time zones side by side, and let AI find the best meeting window — all in one tool.
100% free · No account required · Works in any browser
More than a world clock
Live Clock Cards
Large digital clocks per participant with city name, timezone abbreviation, date, GMT offset, and time-of-day band coloring (Night/Morning/Work/Evening).
24-Hour Global Timeline NEW
Visualize all participants’ days side by side. Drag to set meetings, click cells, use Shift for 5-minute precision. The red NOW line marks current time.
Per-Timezone Work Hours NEW
Not everyone works 9-to-5. Set custom schedules per participant with a 30-minute dual slider. The entire UI adapts instantly.
Dark Mode & Responsive
Auto/Light/Dark themes. Mobile swipe navigation with auto-centering on current time. Horizontal scroll with synced rows.
Holidays & DST Alerts
Public holidays (including Korean substitute holidays), country-specific weekends (Fri/Sat for Middle East), and DST transition warnings one week ahead.
Histogram Heatmap NEW
Variable-height bars replace the old overlap indicator. See exactly how many participants are available at each hour.
Multi-Slot Proposal NEW
Propose up to 3 meeting options at once. Clone to adjacent days with +1d/+2d. Share a link where recipients pick their preferred time.
Perfect for
International Standups
See every team member’s local time at a glance. Know who’s in their morning, who’s wrapping up, and when everyone’s work hours actually overlap.
Client Calls Across Regions
Compare your time with Mumbai, London, or New York. The heatmap shows the sweet spot where everyone’s awake and working.
Travel Planning
Check what time it is back home, at your destination, and for colleagues in other offices — all on one screen.
Remote Collaboration
Share your timezone setup via URL. Teammates open the link and see the exact same view, adapted to their local time.
How it works
Add cities
Search 350+ cities by name, timezone abbreviation (PST, IST, KST), or IANA ID.
Compare at a glance
Live clock cards + 24-hour timeline show every participant’s day side by side with color-coded bands.
Find the overlap
The histogram heatmap highlights peak availability. AI recommends the best meeting slots automatically.
Share or export
Copy the link, export to calendar, or propose up to 3 time options in a single link — recipients pick their preferred slot.
FAQ
How is this different from World Time Buddy?
When2Overlap adds AI-powered meeting recommendations, per-timezone custom work hours, histogram heatmaps, meeting presets, multi-slot proposals (up to 3 options in one link), and full dark mode — all features WTB does not offer. And it’s completely free with no ads.
Which timezones are supported?
All IANA timezones (350+ cities) with Korean and English search. Fractional offsets like India (+5:30) and Nepal (+5:45) are fully supported.
Can I export meeting times?
Yes — ICS files, Google Calendar direct links, clipboard (formatted text), and email. With Multi-Slot Proposals, share up to 3 time options in a single link — recipients pick their preferred slot from selectable cards.
Can I propose multiple meeting options?
Yes. Register up to 3 time options with the “+ Add option” button. Clone to adjacent days with +1d/+2d. Recipients see option cards converted to their local timezone.
Does it work on mobile?
Yes. The timeline switches to horizontal swipe navigation with auto-centering on the current time. Touch drag works for the duration box. Auto/Light/Dark themes all work on mobile.
More than a clock — it’s your scheduling co-pilot
Let AI handle the timezone math for your next meeting.