If you're dispensing at 5 psi, either you're serving beer at near freezing temperatures, or you like flat beer (big cask fan?) or your system isn't set up properly.
A good percentage of beers are best served somewhere around 2.5 volumes of CO2. If you look at that carbonation table, to maintain beer at a reasonable temperature (let's call that around 40°F) at 2.5 volumes of CO2, you need to keep the CO2 pressure around 12 psi. If you can't dispense beer at that pressure for whatever reason, every time you pull a pint your beer is losing carbonation. So, you need to fix your system - most likely make the beer lines much longer than what you're using now.
As for time, I don't think I've ever seen a carbonation chart/table/app that gives the time to fully carbonate the beer. Probably because that's dependent on volume (and lesser factors). As I said before, it takes a good two weeks at a proper carbonation pressure for the beer temperature to bring the beer up to an acceptable level, and another week to be perfect...
Cheers!