It depends on where you live and what paint you have used mostly.
If you used acrylics, and you have humid weather, at least 24 hours drying time, and I would still advise using a low tack masking medium like Tamiya tape.
For enamels I wait 48 hours, the weather here is humid at the moment and it's taking all the paints a while to cure.
Mind you during winter here I can mask and spray inside 2 hours with acrylics and 12 with enamels cause we have super cold dry air during winter.