How can the short story writer manage time with narrative breaks?

It depends whether the narrative is a first person pronoun (I) narrative or a third person pronoun narrative (s/he). Managing time with breaks can be done through introduction of a conversation between two characters or transporting the time to sudden time changes like you find in James Joyce's "stream of consciousness" based novel, Ulysses. 

You may do it by inserting a dialogue or a change of scene - since your intention here is to deviate from the narrator's voice.