one day's sun, ten days' frost (idiom, from Mencius); fig. to work for a bit then skimp
sporadic effort
short attention span
Definitions (Wiktionary)
phrase, figuratively, idiomatic
to work hard for one day and do nothing for ten; to work by fits and starts; to act without perseverance or persistence (syn.) 三天打鱼, 兩天曬網, 两天晒网, 三天打魚