Looking for a word meaning "timescale"

I am sure that I know (or knew) a word that would mean the time it takes for something to occur after setting it in motion.

The closest I can conjure up is "timescale" but that is not what I am looking for. "Duration" is also close, but duration suggests the act is ongoing, rather than occurring later.

I need a phrase which would look something like:

refund "X"

and which should explain to a user that their refund can take up to seven days to process. You can see here how "duration" is not appropriate.