I was aware of this and this stackexchange post discuss the same. There is no prepone in English. Ok, then how do I say Our meeting is preponed in correct way? What is the correct word/phrase for prepone?
Our meeting has been brought forward.
Our meeting has been rescheduled for an earlier time.
I wouldn't worry too much. English is my first language and I liked the word when I first heard it.
Unlike other apparent malapropisms (or eggcorns) this word is succinct, clear in meaning, and it fills a hole.
Unless I've misunderestimated the question?
Just on a whim I checked the dictionary, and it turns out that prepone is in the dictionary! I might personally still avoid it just because many people might be confused by it (or at least take a moment to parse it), but technically it is a perfectly cromulent word.
I then checked the OED and found that this word was coined in 1913. Here is the quote, which comes from the New York Times:
For the benefit mainly of the legal profession in this age of hurry and bustle may I be permitted to coin the word ‘prepone’ as a needed rival of that much revered and oft-invoked standby, ‘postpone’.
In addition to what Ed Guiness said,
Our meeting has been moved to this afternoon.
(Assuming, obviously, that the original time was later than this afternoon, e.g. tomorrow morning.)
Or if you want to give emphasis to the "preponing":
Our meeting has been moved to an earlier time/date: [...]
But go ahead and use "prepone" if you have reason to believe that the people you are addressing are familiar with the term (or at least wouldn't object to using it). :-)