It's only a matter of time before ...

[tzfujimino]

It's only a matter of time before they bring out their own version of the software.
(Source: https://www.oxfordlearnersdictionaries.com/definition/english/matter_1#matter_idmg_4)

Is it acceptable to use "until" instead of "before"?

 

[GoesStation]

Yes.

 

[teechar]

I much prefer the version with "before". Take a look at the ngram.

https://books.google.com/ngrams/gra...me until;,c0;.t1;,a matter of time before;,c0

 

[tzfujimino]

How about "that"?

It's only a matter of time that they bring out their own version of the software.

Does it work?

 

[GoesStation]

How about "that"?

It's only a matter of time that they bring out their own version of the software.

Does it work?

No.