Enforcement of the new Dallas daytime juvenile curfew begins Monday, when the new school year begins.
Punishment includes fines of up to $500.
Students younger than 17 must be in class on school days between 9 a.m. and 2:30 p.m. unless they have a good excuse.
Police supported the measure to combat daytime crime. Officers will enforce it on routine patrol by watching for violators.
"We want to protect the minors from being involved or being a victim of crime, and, of course, we want to protect the public from juvenile violence and juvenile crime," Senior Cpl. Janice Crowther said.
The ordinance was adopted by the Dallas City Council in May after months of debate. Opposition included parents of home-schooled children and business owners.
Business owners objected to provisions that would fine them for allowing curfew violators to be present in their establishments.
"Now we're going to have to go up to anyone that we suspect," said Kathy Doyle Thomas, of Half Price Books. "I think that's where we can really upset a lot of customers, by intruding on them, asking to see their ID or asking for their age."
Half Price Books customers Jonathan Iheke, 15, and his mother, Lovina Iheka, said they support the ordinance.
"Absolutely, l think it's a wonderful idea to keep them in school," Lovina Iheke said.
Her son said some students may use the bookstore as a place to skip classes.
"So looking for IDs to make sure we're supposed to be in school and stuff may be a good idea," Jonathan Iheka said.
Community service and education programs may be offered to offenders as punishment in lieu of fines in Dallas Municipal Court.
"The goal of the court is to actually help them so they do not re-offend and do not commit higher level offenses," Judge Cheryl Williams said.