The proposal seemed simple: Change the length of winter vacation in Los Angeles public schools from three weeks to two. Students would have the same number of school days without losing so much learning momentum.

But the school board’s recent decision to alter winter break and all it affects — the rhythm of lives and coveted time off — has provoked outrage and legal action, and also highlighted the important question of when children should be in school, how effectively time is used and how much say parents and teachers should have over it.

The calendar debate is not limited to Los Angeles or to the length and timing of breaks. Educators in several states, including Michigan and Florida, have explored year-round calendars with shorter but strategically spread out breaks to maximize learning. And in L.A., parents are still complaining about the mid-August start time, when the weather is the hottest and many families want to extend summer activities and travel. Click here to read more: