Zone Planner

The core functions, which every industry uses.

Plan across zones

Pin the zones you care about and drag the slider — every clock moves together. When the slider crosses a daylight-saving boundary, the affected zone's offset changes and is flagged, not silently reflowed. Copy the link to share a proposed time.

The first clock is your own time zone, read from your browser and marked “Your time zone”. Next to it sits a short tour of awkward offsets: Reykjavik, Helsinki, Los Angeles, Shanghai, Calcutta and Katmandu. A link that names zones shows exactly those, with nothing added.

The reference time opens on now, rounded forward to the next five minutes. Every tile says whether its zone is in daylight saving at the time you have scrubbed to, and when your scrub crosses a clock change in that zone the tile names it (“Spring forward +1 h”) and shows the new offset; a mark on the slider’s track shows where each shown zone changes its clocks. “Jump to the next DST transition” goes to the earliest change after the time you are looking at, in any shown zone, spring forward or fall back, and pressing it again goes on to the one after. It lands the slider an hour past the change, with the reference time an hour before it, so you can drag back across it. “Reset to today” puts the reference time back to now.

See it in action: start 15 minutes before New York springs forward in 2026 — drag the slider forward and watch New York’s offset change from UTC-05:00 to UTC-04:00 while London and Tokyo keep ticking normally.