I. ˈ ̷ ̷ˌ ̷ ̷ noun
Etymology: date (II) + line
1. : a line in a written document or a printed publication presenting the date of composition or issue: as
a. : the line at the beginning of a nonlocal news story giving its date and place of origin
b. : a line or space in a publication giving the date of issue, the volume number, and the issue number
2. usually date line : a hypothetical line on the earth's surface coinciding with the 180th meridian except where it is deflected between north latitudes 48° and 75° and between south latitudes 15° and 51° to avoid dividing places in close intercourse and designated arbitrarily as the place where each calendar day first begins
3. : deadline 3
II. transitive verb
: to provide with a dateline
a dispatch datelined Chicago