daylight-saving time

[dey-lahyt-sey-ving] /ˈdeɪˌlaɪtˈseɪ vɪŋ/
noun
1.
the civil time observed when daylight saving is adopted in a country or community.
Also, daylight-savings time.
Origin
1905-10
British Dictionary definitions for daylight-saving time

daylight-saving time

noun
1.
time set usually one hour ahead of the local standard time, widely adopted in the summer to provide extra daylight in the evening Also called (in the US) daylight time See also British Summer Time
daylight-saving time in Science
daylight-saving time
  (dā'līt-sā'vĭng)   
Time during which clocks are set one hour or more ahead of standard time to provide more daylight at the end of the working day during late spring, summer, and early fall. First proposed by Benjamin Franklin, daylight saving time was instituted in various countries during both world wars in the 20th century and was made permanent in most of the United States beginning in 1973. Arizona, Hawaii, most of eastern Indiana, and certain US territories and possessions do not observe daylight saving time.