This video was published by the US Department of Education in April 2018.
"As early as elementary school, students who miss just two school days each month are more likely to fall behind in reading, writing and math, even if the absences are excused. While some challenges to a child’s attendance are unavoidable, it’s important to understand the impact of each absence. A student is chronically absent if he or she misses only two days of school per month (18 days per year). Even one year of chronic absence can cause a child to fall behind academically and decrease a child’s chances of graduating from high school, which can have long-term consequences on their financial independence, physical well-being and mental health. Parents can prepare their children for a lifetime of success by making regular school attendance a priority and understanding the reasons for their child’s absences."