I was told that the CPVC joints should glue dry for 24 hours before connecting water.

Is this true?

Read instructions on the can. It will tell you what's the drying time for that particular glue.

From my experience, heavy body PVC glue can hold household pressure in about 15 minutes.

Indeed, instructions on the box say 24 hours.
It is CPVC, not PVC.

Thank you.

It pays to read the label. I hope you used the all purpose glue and not pvc glue.

Oh, sure, go always what manufacturer suggests...

With purple primer and orange cpvc glue, allow 12 to 24 hour dry time according to manufacturers suggestions... or, it you want to do it like I do it, wait about an hour... I've waited as little as 15 or 20 minutes though and never had a problem... use pex though, and avoid waiting, water solvency issues, and freezing issues... copper, cpvc, etc: old news.. PEX is where its at