Context Help: Time

OpenFlights tries to understand local time, so you can enter local departure and arrival times and have the actual flight duration computed automatically. If you enter only a departure time, OpenFlights will estimate the flight duration based on the length of the flight and suggest an arrival time.

To see the timezones and DST status of current airports when adding or editing flights, hover your mouse over the clock icon.


Internal consistency between date, time, flight duration and flight distance is enforced as follows:

Changing this...  recalculates these
Arrival time Duration Distance
Airport Yes Yes Yes
Arrival time Yes No
Duration Yes No
Distance No No
Date Yes No No
Departure time Yes No No

Time zones

OpenFlights uses UTC offsets as timezones, so UTC+8 (Singapore) is recorded as "+8" and UTC-5 (New York) as "-5". Time zone data for OpenFlights was obtained from EarthTools.

Daylight Savings Time (DST)

When active, Daylight Savings Time (DST), or "summer time", adds one to the normal timezone, so e.g. New York, normally UTC-5, becomes UTC-4 while DST is active. OpenFlights currently understands the following types of DST:

The rules for DST change constantly and not all airports are up-to-date or marked correctly. Please contact the OpenFlights team if you find any errors.


A flight in April departs Singapore (SIN) at 20:00 and arrives in Chennai (MAA) at 21:30. Singapore is UTC+8, Chennai is UTC+5.5. Flight duration is thus (21:30-20:00) - (05:30-08:00) = 1:30 - (-2:30) = 4:00.

A flight in June departs Newark (EWR) at 23:00 and arrives in Singapore (SIN) at 07:40 + 2 days. Singapore is UTC+8, New York is UTC-4 (DST). Flight duration is thus (07:40+48:00)-23:00 - (-04:00-08:00) = -32:40 - -(12:00) = 20:40.