Passage planning

Sunrise & sunset

Daylight, twilight, and day length for a position and date.

Inputs

Latitude (° , N positive)

Longitude (° , E positive)

Date

Time zone (hours from UTC)

Result (local time)

Civil twilight begins—

Sunrise—

Solar noon—

Sunset—

Civil twilight ends—

Day length—

Uses the NOAA solar-position equations (accurate to about a minute at mid-latitudes), with the standard 90.833° zenith for sunrise/sunset and 96° for civil twilight. Atmospheric refraction varies with conditions, and the time zone is entered manually — remember daylight saving time.