終日 (shūjitsu) means “all day” | MotiTan Japanese Dictionary

More examples

大雨のため、電車は終日運休しています。ō ame no ta me den sha wa shū jitsu un kyū shi te i ma su

Train service is suspended all day because of heavy rain.

The meaning centers on covering the complete span of one day rather than a limited part of it.

一日中ichinichijū: Shows that an action or condition lasts through the whole day in ordinary speech.

一日の初めから終わりまで続くさま。ichi nichi no haji me ka ra o wa ri ma de tsuzu ku sa ma

終日 (shūjitsu) is a Sino-Japanese compound of 終 (shū, "end") and 日 (jitsu, "day"), expressing a day taken as a complete span.

In Japanese notices, 終日 (shūjitsu) commonly marks a service or facility as available throughout the day, giving the expression a formal tone.