daylight saving time; summer time
Refers to the practice of advancing clocks during summer months. The more common term is 夏時間 (なつじかん).
See also: 夏時間
When daylight saving time starts, the days feel longer.
Compound of 夏 (summer) and 時刻 (time). The exact historical derivation is uncertain; the term is a straightforward calque or translation of English 'summer time' or 'daylight saving time'.