|Native name||دی (Persian)|
|Calendar||Solar Hijri calendar|
|Number of days||30|
Dey (Persian: دی, Persian pronunciation: [dei̯]) is the tenth month of the Solar Hijri calendar, the official calendar of Iran and Afghanistan. It marks the start of winter. It has thirty days, beginning in December and ending in January of the Gregorian Calendar.
- 10 - 1363 - In a public ceremony in Bandar Seri Begawan, Sultan of Brunei Hassanal Bolkiah declares Brunei as an sovereign, independent nation.
- 5 - 1370 - Dissolution of the Soviet Union
- 6 - 1383 - Boxing Day tsunami
- 9 - 1388 - Conservative counterdemonstrations during 2009–10 Iranian election protests. Commemorated by hardline figures.
- 27 - 1345 - Super Bowl I held at the Los Angeles Memorial Coliseum in Los Angeles, California between the National Football League and the American Football League.
- 5 - 1351 - Harry S. Truman, 33rd President of the United States
- 5 - 1385 - Gerald Ford, 38th President of the United States
- 13 - 1391 - Ayatollah Mojtaba Tehrani, was an Iranian Twelver Shi'a Marja' taqlid.
- 15 - 1311 - Calvin Coolidge, 30th President of the United States
- 15 - 1297 - Theodore Roosevelt, 26th President of the United States
- Khorram rooz - 1 Dey
- Christmas Eve - 3 or 4 Dey
- Christmas - 4 or 5 Dey, celebrated by Christians of Iranian descent who use the Gregorian Calendar (Georgian date: December 25)
- Boxing Day - 5 or 6 Dey
- New Year's Day (Gregorian calendar) - 10 or 11 Dey
- Zartosht No-Diso - 11 Dey (Zoroastrian holiday, one of the most holy days of Zoroastrianism)
- Traditional Epiphany and Armenian Christmas - 16 or 17 Dey
- Ethiopian Christmas - 17 or 18 Dey
- Feast of the Baptism of the Lord - 23 Dey (Traditional), fourth Sunday of Dey (modern)
- Traditional Epiphany (Julian Calendar) - 29 or 30 Dey
For those countries that observe Epiphany on the first Sunday of January following the New Year, the Solar Hijri date falls as the third Sunday of Dey.
- "Months and Seasons - Persian Vocabulary". 2014. Retrieved September 8, 2014.