School Year Dates

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Mt. Diablo Unified school calendar 2026-27

First day, last day, breaks, holidays and teacher workdays, read from the district's own calendar.

Open the district's calendar (resources.finalsite.net)Add to your calendar (.ics)

Independent site, not affiliated with any school district. School Year Dates is an independent publisher. We are not affiliated with, endorsed by or operated by Mt. Diablo Unified or any other school district. Official calendar: resources.finalsite.net.

First day
Fall Recess
to
School Recess
to
Winter Recess
to
Spring Recess
to
Last day

Kindergarten, pre-K, individual grades and particular schools may have different start dates or schedules. Check the district calendar for your child's grade and school.

Unmarked weekdays and computed counts use only the breaks, holidays and teacher workdays listed here. Other closures may be missing, so these are potential weekdays, not verified days of attendance.

Month by month

  • Weekday in term
  • Break
  • Holiday
  • No students (teacher workday)
  • Early release
  • First day
  • Last day
August 2026
SMTWTFS
1
23 All Teacher In-Service Day- Non Student Day45 All Teacher In-Service Day- Non Student Day6 First day of school7 Weekday in term8
910 Weekday in term11 Weekday in term12 Weekday in term13 Weekday in term14 Weekday in term15
1617 Weekday in term18 Weekday in term19 Weekday in term20 Weekday in term21 Weekday in term22
2324 Weekday in term25 Weekday in term26 Weekday in term27 Weekday in term28 Weekday in term29
3031 Weekday in term
September 2026
SMTWTFS
1 Weekday in term2 Weekday in term3 Weekday in term4 Weekday in term5
67 Labor Day8 Weekday in term9 Weekday in term10 Weekday in term11 Weekday in term12
1314 Weekday in term15 Weekday in term16 Weekday in term17 Weekday in term18 Weekday in term19
2021 Weekday in term22 Weekday in term23 Weekday in term24 Weekday in term25 Weekday in term26
2728 Weekday in term29 Weekday in term30 Weekday in term
October 2026
SMTWTFS
1 Weekday in term2 Weekday in term3
45 Fall Recess6 Fall Recess7 Fall Recess8 Fall Recess9 Fall Recess10
1112 Indigenous Peoples Day13 Weekday in term14 Weekday in term15 Weekday in term16 Weekday in term17
1819 Weekday in term20 Weekday in term21 Weekday in term22 Weekday in term23 Weekday in term24
2526 Teacher In Service- Non Student Day27 Weekday in term28 Weekday in term29 Weekday in term30 Weekday in term31
November 2026
SMTWTFS
12 Weekday in term3 Weekday in term4 Weekday in term5 Weekday in term6 Weekday in term7
89 Weekday in term10 Weekday in term11 Veterans Day12 Weekday in term13 Weekday in term14
1516 Weekday in term17 Weekday in term18 Weekday in term19 Weekday in term20 Weekday in term21
2223 School Recess24 School Recess25 School Recess26 School Recess; Thanksgiving Day27 School Recess; Board Holiday28
2930 Weekday in term
December 2026
SMTWTFS
1 Weekday in term2 Weekday in term3 Weekday in term4 Weekday in term5
67 Weekday in term8 Weekday in term9 Weekday in term10 Weekday in term11 Weekday in term12
1314 Weekday in term15 Weekday in term16 Weekday in term17 Weekday in term18 Weekday in term19
2021 Winter Recess22 Winter Recess23 Winter Recess24 Winter Recess25 Winter Recess; Christmas Holiday26 Winter Recess
27 Winter Recess28 Winter Recess29 Winter Recess30 Winter Recess31 Winter Recess
January 2027
SMTWTFS
1 Winter Recess; New Year's Day2
34 Weekday in term5 Weekday in term6 Weekday in term7 Weekday in term8 Weekday in term9
1011 Weekday in term12 Weekday in term13 Weekday in term14 Weekday in term15 Weekday in term16
1718 Martin Luther King Day19 Weekday in term20 Weekday in term21 Weekday in term22 Weekday in term23
2425 Weekday in term26 Weekday in term27 Weekday in term28 Weekday in term29 Weekday in term30
31
February 2027
SMTWTFS
1 Weekday in term2 Weekday in term3 Weekday in term4 Weekday in term5 Weekday in term6
78 Weekday in term9 Weekday in term10 Weekday in term11 Weekday in term12 Weekday in term13
1415 Presidents Day16 Weekday in term17 Weekday in term18 Weekday in term19 Weekday in term20
2122 Weekday in term23 Weekday in term24 Weekday in term25 Weekday in term26 Weekday in term27
28
March 2027
SMTWTFS
1 Weekday in term2 Weekday in term3 Weekday in term4 Weekday in term5 Weekday in term6
78 Weekday in term9 Weekday in term10 Weekday in term11 Weekday in term12 Weekday in term13
1415 All Teacher In-Service Day- Non Student Day16 Weekday in term17 Weekday in term18 Weekday in term19 Weekday in term20
2122 Weekday in term23 Weekday in term24 Weekday in term25 Weekday in term26 Weekday in term27
2829 Weekday in term30 Weekday in term31 Weekday in term
April 2027
SMTWTFS
1 Weekday in term2 Farmworkers Day3
45 Spring Recess6 Spring Recess7 Spring Recess8 Spring Recess9 Spring Recess; Board Holiday10 Spring Recess
11 Spring Recess12 Spring Recess13 Weekday in term14 Weekday in term15 Weekday in term16 Weekday in term17
1819 Weekday in term20 Weekday in term21 Weekday in term22 Weekday in term23 Weekday in term24
2526 Weekday in term27 Weekday in term28 Weekday in term29 Weekday in term30 Weekday in term
May 2027
SMTWTFS
1
23 Weekday in term4 Weekday in term5 Weekday in term6 Weekday in term7 Weekday in term8
910 Weekday in term11 Weekday in term12 Weekday in term13 Weekday in term14 Weekday in term15
1617 Weekday in term18 Weekday in term19 Weekday in term20 Weekday in term21 Weekday in term22
2324 Weekday in term25 Weekday in term26 Weekday in term27 Weekday in term28 Weekday in term29
3031 Memorial Day
June 2027
SMTWTFS
1 Weekday in term2 Last day of school345
6789101112
131415161718 Juneteenth (Observed)19
20212223242526
27282930

The 2026-27 year in words

Classes for Mt. Diablo Unified run from until . End to end that is roughly 43 weeks, and after the breaks, holidays and teacher workdays are removed, 180 potential weekdays remain, based only on the exceptions listed here. Because the year opens on a Thursday, the first week contains two potential weekdays after listed closures; the final week contains two to the Wednesday finish.

There are 4 breaks on the calendar. Fall Recess starts and ends , a total of 5 days with 5 weekdays off. Students are off for School Recess from to , 5 days counting weekends and 5 weekdays counting Monday through Friday. Winter Recess: to , which is 12 days and 10 weekdays without classes. Spring Recess runs through : 8 days off the calendar, 6 of them weekdays. Winter Recess is the longest break, 12 days from start to finish.

Between and there are 34 potential weekdays with no listed closure, the longest such run in this summary. After subtracting listed closures, winter break divides the remaining potential weekdays into 83 before it and 97 after it.

9 other days off are marked as holidays: Independence Day (Observed) (), Labor Day (), Indigenous Peoples Day (), Veterans Day (), Martin Luther King Day (), Presidents Day (), Farmworkers Day () and Memorial Day (), and 1 more. 8 of these fall on a Monday or Friday and make a long weekend: Independence Day (Observed), Labor Day, Indigenous Peoples Day, Martin Luther King Day, Presidents Day, Farmworkers Day, Memorial Day and Juneteenth (Observed).

6 teacher workdays without students are listed, the first on and the last on .

Among the 14 California districts on this site, Mt. Diablo Unified starts earlier than 10 and later than 1, on the same day as 2 others. The median first day in the group is . The earliest first day on the site in California is (San Bernardino City Unified) and the latest is (Orange Unified).

The source describes this calendar as approved. Approved calendars still change: weather days, board votes and contract settlements can move dates, so confirm anything you are planning around.

The dates come from a PDF calendar at resources.finalsite.net, last read on . Use the link on this page to open the district's own calendar and confirm.

Dates in detail

Breaks
BreakStartsEndsDaysWeekdays
Fall Recess55
School Recess55
Winter Recess1210
Spring Recess86
Holidays
DayDate
Independence Day (Observed)
Labor Day
Indigenous Peoples Day
Veterans Day
Thanksgiving Day
Board Holiday
Christmas Holiday
New Year's Day
Martin Luther King Day
Presidents Day
Farmworkers Day
Board Holiday
Memorial Day
Juneteenth (Observed)
Teacher workdays (no students)
DayDate
New Staff Orientation
New Staff Orientation
All Teacher In-Service Day- Non Student Day
All Teacher In-Service Day- Non Student Day
Teacher In Service- Non Student Day
All Teacher In-Service Day- Non Student Day
Potential weekdays by month, after listed exceptions
MonthPotential weekdays
August 202618
September 202621
October 202615
November 202615
December 202614
January 202719
February 202719
March 202722
April 202715
May 202720
June 20272

Where these dates come from

Source: resources.finalsite.net (a PDF calendar), read on . Districts revise calendars after severe weather, board votes and contract settlements, so the district's own page is the version that counts. If a date here looks wrong, tell us and we will re-check the source. How we check.

Other California districts

Districts in California close in size to Mt. Diablo Unified, with their own calendars on this site:

All California districts