Incidents of child abuse increase the day after school report cards are released—but only when kids get their grades on a Friday, according to a new study conducted in Florida. The study compared data from a child-abuse hotline to the dates when grades were released, showing an increase in reports of child abuse only on Saturdays after a report-card Friday. There were almost four times more cases on those Saturdays than on other Saturdays, according to the study. Researchers said they were surprised by the results, expecting abuse to go up after grades, but regardless of what day they were given. Some researchers speculated that parents may become more abusive when kids don’t have school the next day and parents think injuries might be less visible by Monday when teachers could notice. Or, researchers also suggested that severe punishment might be less likely on weekdays when parents are busier.