Tools ›Cartage ›TZ Window

Time-Zone Delivery Window Planner

Translate a receiver-local business window into dispatcher-local time, DST-aware. Pick the pickup date, both zones, and receiver hours — get the same window in the dispatcher's clock plus a next-day-rollover flag.

Trip

Pickup date

Zones

Origin (dispatcher)

Destination (receiver)

Receiver window

Start (24-hr)

End (24-hr)

Hours are receiver-local. 24-hour clock (08 = 8am, 17 = 5pm).

Formula

Offset (hr) = origin UTC offset − destination UTC offset, evaluated at the pickup date so DST is applied correctly for each zone.
Dispatcher window = receiver window translated by the offset; date shifts ±1 day when the translation crosses midnight in one zone but not the other.
DST-aware Offsets come from IANA rules via Intl.DateTimeFormat, applied to the specific pickup date.

Source: IANA time-zone database (public domain), consumed via the Node.js runtime Intl APIs. No third-party service.