subject-inverted form of il y a; is there? are there?, (after a modal adverb) there is, there are

(idiomatic) you shouldn't have (said on receiving a gift)

what time is it?

there was once…; once upon a time, there was… (traditional beginning of children’s stories, especially fairy tales)

how's the weather?

(informal) as expected

what time is it?

the fact remains that

not at all

(colloquial) it's about time, it's high time