whens

(interrogative) At what time? At which time? Upon which occasion or circumstance? Used to introduce direct or indirect questions about time.

(relative) At which, on which, during which: often omitted or replaced with that.

(fused relative) The time at, on or during which.

(informal, in definitions or explanations) A circumstance or situation in which.

(interrogative, Internet slang, often humorous) Used after a noun or noun phrase in isolation to express impatience with an anticipated future event.

At an earlier time and under different, usually less favorable, circumstances.

The time at which something happens.