noun
government-recommended summer lifestyle adjustments for long daylight hours
Abbreviation of ゆうやけ時間活動推進. Refers to a Japanese government campaign encouraging people to shift daily activities earlier to make better use of daylight in summer, such as starting work earlier and enjoying evening leisure.
See also: ゆうやけ時間活動推進
今年の夏はゆう活を実践して、早めに仕事を終わらせよう。
Let's practice 'yūkatsu' this summer and finish work early.
ゆう活で夕方の時間を有効に使う人が増えている。
More people are using their evening hours effectively through yūkatsu.
Full official name of the campaign; ゆう活 is the common abbreviation.
Abbreviation of ゆうやけ時間活動推進 (yūyake jikan katsudō suishin), a government campaign name. The exact derivation is straightforward: ゆう (evening) + 活 (activity, from 活動).