That really depends on the capability of the person doing the work.
If you are doing it yourself, time really doesn't matter.
If you are jobbing it out, it is best to ask them.
Secondly what vintage of an airplane is it. If it is an older non-prepunched 4-6 or?? You might check with Van's if you can get a skin. They didn't have a prepunched skin for an RV-6 when I checked a year ago.
And they said they may not be stocking them anymore.
BUT your luck may vary Art
If you have all the tools, especially a 12” #30 bit, you can unskin and reskin in about 4 hours. This assumes you don’t mess up anything on the skeleton while drilling off the pop rivet heads.