Official Mount Sinai 2026-2027 school calendar with holidays, breaks, PDF, and calendar sync. Complete school year calendar for Mount Sinai School District, Suffolk County. Includes all holidays, breaks, half days, and important dates from September 2026 through June 2027. Dates are manually collected and screened from district-published calendar materials. Printable PDF and Google/Apple Calendar sync options are available below. Updated March 17, 2026.
| Event | Date(s) | Status |
|---|---|---|
| First Day of School | September 8, 2026 (Tue) | School Opens |
| Yom Kippur | September 21, 2026 (Mon) | No School |
| Columbus Day | October 12, 2026 (Mon) | No School |
| Thanksgiving Recess | November 25, 2026 - November 27, 2026 | No School |
| Winter Recess | December 24, 2026 - January 1, 2027 | No School |
| Martin Luther King Jr. | January 18, 2027 (Mon) | No School |
| Midwinter Recess | February 15, 2027 - February 19, 2027 | No School |
| Spring Recess 1 - Easter | March 26, 2027 (Fri) | No School |
| Spring Recess 1 - Easter | March 29, 2027 (Mon) | No School |
| Spring Recess 2 - Passover | April 19, 2027 - April 23, 2027 | No School |
| Memorial Day | May 31, 2027 (Mon) | No School |
| Last Day of School | June 25, 2027 (Fri) | School Closes |
View the full 2026-2027 school year by month.
Mount Sinai School District is listed here with official 2026-2027 calendar data. The student year starts on Tuesday, September 8, 2026 and ends on Friday, June 25, 2027.
The main multi-day closure blocks are Thanksgiving Recess (Wednesday, November 25, 2026 through Friday, November 27, 2026), Winter Recess (Thursday, December 24, 2026 through Friday, January 1, 2027), Mid-Winter Recess (Monday, February 15, 2027 through Friday, February 19, 2027), Spring Recess 2 - Passover (Monday, April 19, 2027 through Friday, April 23, 2027).
Single-day closures and important calendar items include Yom Kippur (Monday, September 21, 2026), Columbus Day (Monday, October 12, 2026), Veteran's Day (Wednesday, November 11, 2026), Martin Luther King Jr. (Monday, January 18, 2027), Spring Recess 1 - Easter (Friday, March 26, 2027), Spring Recess 1 - Easter (Monday, March 29, 2027), Unused Snow Day (If needed) (Monday, May 17, 2027), Unused Snow Day (If needed) (Thursday, May 27, 2027), plus additional dated items in the table below.
Data source & handling: Official calendar from Mount Sinai School District (mtsinai.k12.ny.us). We manually collect and screen dates from district materials, then organize them into key dates, printable PDF, and calendar sync.
Disclaimer: This site is not affiliated with Mount Sinai School District or NYSED. Official calendars can change - always check mtsinai.k12.ny.us before making plans.
Last updated: March 17, 2026