📰 News location line 🌏 International date line 🗓️ To mark with date

dateline

3 6.6

Imaginary line near the middle of the Pacific Ocean where the calendar date changes

noun
/ˈdeɪtˌlaɪn/

Specialized

: línea internacional de cambio de fecha

When traveling from Hawaii to Tokyo, you cross the dateline and lose a day.
the international dateline
cross the dateline

Examples

As far as I can tell, the poor bastard never rounded the Cape, or crossed the dateline.

The Mercy (2018)
And they include calendars, clocks, the International Date time, dateline, all of which are quite recent inventions in terms of human history.
Bernice, Ben lives in Japan, on the other side of the international dateline.

Blog text (10)
An important feature of warm episodes is the development of enhanced convection along the equator in the vicinity of the dateline.

Academic text (1997)
The international dateline runs along the 180th meridian, marking where each new day starts.
Sailing across the dateline can often cause confusion about what day it is.

Synonyms

date line

vsdateline

2 5.7

An imaginary line near the middle of the Pacific Ocean where the calendar date changes when you cross it

is the one-word spelling commonly used for the same north to south line

International Date Line

vsdateline

2 5.1

An invisible line in the middle of the Pacific where the calendar date changes when crossed

is the shorter common name used for the same imaginary line

Surface Forms

dateline singular

datelines plural

Morphology

dateline = date + line (semi-transparent) = date + line

While the compound literally means a 'line' related to 'date', the sense refers to a specific geographic/astronomical boundary (International Date Line), which is a specialized concept beyond simple compounding.

Etymology

Dateline also means the imaginary line on the world map where the calendar day changes. It is literally a date ('day') line, so when you cross it your calendar moves forward or back one day.