They changed it at a BoE meeting last May. See discussion here: https://www.dcurbanmom.com/jforum/posts/list/60/1097028.page

They swapped Feb. 16 with May 14 after the primary election date was announced for May 14. Schools are required to be closed on election day.

When did the BOE change the calendar so that Feb 16 was a day off?

According to the wayback machine (archives), Feb 16, 2024, was marked as a professional day as of April 24, 2023 (source: https://web.archive.org/web/20230424042949/https://ww2.montgomeryschoolsmd.org/uploadedFiles/calendar/2023-24_TraditionalCalendar.pdf)

However, by September 21, 2023, it was no longer marked as a professional day (source: https://web.archive.org/web/20230921160818/https://ww2.montgomeryschoolsmd.org/uploadedFiles/calendar/2023-24_TraditionalCalendar.pdf)

I thought they couldn’t make changes like that so late?