This study explored the contribution of physical education and recess to children's physical activity (PA) behavior and examined whether they compensate for missed PA opportunities. Participants' (N = 115; age: 9.2 ± 0.6 years) PA was measured using accelerometry across multiple time periods, including data from school days and weekends. Data collection occurred over 6-7 weeks, with 2 weeks in between each period. Physical education and recess accounted for 22.98% (SD = 8.32) and 19.71% (SD = 6.87) moderate-to-vigorous PA, and 16.06% (SD = 4.54) and 14.65% (SD = 4.45) total PA, respectively. Analyses revealed differences between physical education and non-physical education days (Wilks's [lambda] = 0.80, p < 0.001; partial [eta][superscript 2] = 0.20) and physical education and weekend days (Wilks's [lambda] = 0.67, p < 0.001; partial [eta][superscript 2] = 0.33). Physical education contributed to habitual PA more than previously thought; schools should be increasing, not reducing, opportunities.