What's the opposite of "extending the deadline"?

Extending or pushing a deadline means giving more time to work on a project. But what if you want to say you are changing it so that the task is due sooner?

What are the words or expressions I could use?

Solution 1:

Most often you will encounter moving up the deadline.

Solution 2:

One would shorten a deadline.

Solution 3:

Looking up dictionaries I found that prepone is actually a legitimate word.

to reschedule to an earlier day or time: Our Wednesday meeting has been preponed to Tuesday afternoon at 3:00.

It makes sense etymologically as well since postpone is a composite of post (after) and pone (place, position). Example sentences using the words prepone and preponement can be found here.

EDIT: As per the OED this word has etymological roots in Latin very much the same as the corresponding antonym. It derives from the classical Latin word praepōnere meaning to place in front.