Calendar Confusion: Unpacking Variation in the Four-Day School Week

The difference between a five-day school week (5DSW) and a four-day school week (4DSW) seems straightforward. But in practice, it's not clear how different 4DSW and 5DSW calendars actually are—or how much variation exists among districts that share the same label. Documenting variation in school schedules is important for interpreting the mixed evidence we have on effects of the 4DSW. With that in mind, this brief leverages longitudinal data on daily school operation status from Texas to systematically document how school calendars vary. It has three parts: 

• First, we examine how calendar structures differ within and between 4DSW and 5DSW districts, and how these structures have changed over time.
• Next we compare observed calendar features across four different measures of 4DSW status and across district characteristics.
• Finally, we highlight cases in which a district’s calendar “identity” appears misaligned with its calendar structure.

What we find complicates the intuition that the 4DSW represents a consistent policy treatment and shows how classification choices can shape conclusions about its effects.