It's that time of year again. It's the time of year when people dress up in their best costumes and knock on the door and demand candy or, as it's better known, go trick-or-treating.

This tradition of celebrating Halloween can be traced all the way back to the 17th century, but ultimately what everyone wants to know is when they can start raking in the free, delicious, sweet treats. So...

When does trick-or-treating start?

Long story short, it varies from town to town but there are a few traditions that ring true no matter where you live.

The first is that you can expect to see the young ones -- think babies, toddlers, and grade school-aged children -- earlier in the night. According to Country Living, this means around sunset (5:30 p.m. - 6:00 p.m.). To be safe, though, start preparing for around the time school ends, since Halloween lands on a school night this year.

Teenagers will likely wait until its fully dark out to begin trick-or-treating, but no need to worry about them ringing your doorbell in the middle of the night. A poll cited by Good Housekeeping reported that most Americans had finished their candy acquisition by 9 p.m. -- just in time to catch some Halloween TV specials.

Double-check local laws and news reports to be sure of trick-or-treating times in your neighborhood. Some areas have strict curfew laws, and it'd be a shame to get a ticket.

Happy Halloween!

Halloween Candy
Representational image of children in costumes being given candy during Halloween festivities in Santiago, Chile Oct. 31, 2015. MARTIN BERNETTI/AFP/Getty Images