My guideline was 3 days but I'm itching to water my new plants

With plants that I have had for a while and I haven't had to mess with their roots at all I tend to water them right after. If they are new and I have to wash off the roots then I try to wait a few days. It gives you some room in case they have been watered too much before I got them.

I think it depends on how wet the plant was when you repotted it and also how wet the new potting mix was that you used in the repot. If it was damp when you repotted it wait a while, if not wait a day or two.

I've got a repot I'm itching to water as well. It's outside, but the plant was damp when I repotted it and so was the new mix. Also we've had a couple days of high humidity, so I am holding off on the watering several days or more even though it's in the high 90s.

I wait three days. Any bruising of the roots can lead to rot if watered too soon. Why chance it when the plants think nothing of a little dryness.

Sometimes, depending of the plant, I will water before I repot, as long as I do not intend to mess with the roots. It clumps the soil and makes much less of a mess.