This has probably already been asked, sorry, but just curious?

I think it's every 30 minutes.

Trick or Treating, like Blackokami, I think is 30 mins. TPing is a different amount of time I think, a couple hours. I don't know about egging.

: If you want to know exactly when you can trick-or-treat again, click the Make an Alert link.

Okie, that's cool. Thanks for the help!

or you could just try trick or treating again and it'll say:

"you can't trick or treat for -insert time here- more minutes"

It varies though. I had a 30 min one and then recently a 10 min one.

I think it's pretty random like Bronx said. I don't think the alert system is working for this, is it?

The alert system is working for trick-or-treating, but not for egging or TP.