Timezone Comparator
Compare times across timezones. Click or drag to select a time, reorder rows, switch to week view.
How it works
Each timezone is a horizontal strip of 24 hours, color-coded by time of day. Business hours (9 AM – 5 PM) appear in green. A vertical now-line marks the current time across all strips. Click or drag to select any hour — the selected column highlights across all timezones. The overlap summary shows shared working hours.
Switch to Week view to see 7 days at a glance. In week view, business hours (9–17) are shown by default for a compact view. Toggle "All hours" to see the full 24h heatmap for each day. Drag the grip handle to reorder rows. Click any cell to copy the time to your clipboard.
On mobile, the day view shows a focused 9-column window centered on your selection (or current time) for easier reading. The visible window re-centers as you drag across the timeline. Selected timezones and view mode are saved in the URL for sharing.
The overlap algorithm checks each UTC hour against working hours (9:00–17:00) in every timezone. An hour counts as overlapping only if it falls within business hours in all timezones simultaneously. Daylight saving time is handled automatically via the browser's Intl API.
FAQ
How do I find overlapping business hours across timezones?
Add timezones with the search box. The color-coded grid shows business hours in green. The overlap summary below the strips tells you exactly which hours are shared across all selected timezones.
What counts as business hours?
9:00 AM to 5:00 PM local time in each timezone. Overlap is calculated where all timezones are simultaneously within this range.
How do I share my comparison?
Timezones are saved in the URL automatically. Copy and share the link.
Does it handle daylight saving time?
Yes. The Intl API handles DST transitions automatically. Offsets always reflect the current DST status.
How does the week view work?
Week view shows 7 days (Monday–Sunday) as color-coded blocks. By default only business hours (9–17) are shown for a compact overview. Toggle "All hours" to see the full 24h heatmap. Click or drag to select times across the week.
How many timezones can I compare?
No hard limit. 3–6 works best for readability.