Where the heck did they come from?

Now I know why I see school kids walking home both at 1:00 in the afternoon and at 7:00 in the evening. They are not in school for 9 hours; the day is split. In St. Luceo Theresa de los Andes for instance the equivalent of middle and high school kids the day ends at 1:30 for most. I stayed for the senior English class for the first time today. I was startled to see tiny kids running amuck in the courtyardgymatorium (the courtyard which serves as a gym which serves as an auditorium.) I am really proud of that word. Anyway, as the weenie kids lined up, I found myself asking where the heck they had originated. They came for the second shift, coming at 1:30 and leaving at 7. Up until this point I had no idea that there were kids here younger than 11. I wonder if this is done to conserve space. It is not done to conserve teachers, because different ones come in at this time.