| October 2003 | Ocean | Occitan language |
| OctalThe octal numeral system is the base 8 number system, and uses the digits 0 7. According to Donald Knuth's The Art of Computer Programming it was invented by King Charles XII of Sweden. Octal numerals can be made from binary numerals by grouping consecuti | OctoberOctober is the tenth month of the year in the Gregorian Calendar, with 31 days. From the Latin octo for " eight" (it was originally the eighth month of the year, before January and February were inserted). Holidays Halloween Thanksgiving Day in Canada on | October 25October 25 is the 298th day of the year (299th in leap years) in the Gregorian Calendar, with 67 days remaining. Events 1415 The army of Henry V of England defeats the French army at the Battle of Agincourt 1662 King Charles II of England sells Dunkirk to |
| October 1October 1 is the 274th day of the year (275th in Leap years). There are 91 days remaining. Events 331 BC Alexander the Great defeats Darius III of Persia in the Battle of Arbela 959 Edgar the Peaceable becomes king of all England 965 John XIII becomes Pop | October 28October 28 is the 301st day of the year (302nd in leap years) in the Gregorian Calendar, with 64 days remaining. Events 306 Maxentius is proclaimed Roman emperor. 312 Battle of Milvian Bridge: Constantine the Great defeats the forces of Maxentius. Roman e | October 24October 24 is the 297th day of the year (298th in leap years) in the Gregorian Calendar, with 68 days remaining. Events 69 Second Battle of Bedriacum, forces under Antonius Primus, the commander of the Danube armies, loyal to Vespasian, defeat the forces |
| October 3October 3 is the 276th day of the year (277th in Leap years). There are 89 days remaining in the year. Events 2333 BC Legendary date of the establishment of the Kingdom of Chosun ( Korea) 42 BC First Battle of Philippi: The Triumvirs Mark Antony and Octav | October 17October 17 is the 290th (in leap years the 291st) day of the year according to the Gregorian calendar. There are 75 days remaining. Events 1244 Battle of La Forbie: Crusaders were defeated by Khwarezmians & Egyptians 1346 Battle of Neville's Cross: King D | October 10October 10 is the 283rd day of the year (284th in Leap years). There are 82 days remaining. Events 680 Battle of Karbala: Shia Imam Husayn bin Ali, the grandson of the Prophet Muhammad, was decapitated by forces under Caliph Yazid I. This is commemorated |
| October 26 | October 27 | October 29 |
| October 30 | October 31 | October 11 |
| October 20 | October 7 | October 4 |
| Octahedron | Octans | Occult |
| October 14 | October 2 | October 12 |
| October 5 | October 6 | October 8 |
| October 18 | October 9 | October 13 |
| October 15 | October 16 | October 19 |
| October 21 | October 22 | October 23 |
| Octapad | Oceania | OCR |
| Occam | Occam programming language | October Revolution |
| Occidental | Occidental language | Octopus |
| OC-135 Open Skies | Occidental College | Occam's Razor |
| Octave | Octet | Ocaml |
| Oceanography | Occupational therapy | Occupied territories |
| Oceanus | Octonion | Oceanside |
| Ocean thermal energy conversion | Octavia | Oceanid |
| Ochazuke | Ochimus | Ocridion |
| Ocyrhoe | Ocnus | Ocalea |
| Occator | Occupied Japan | Oconto County, Wisconsin |
| Ochiltree County, Texas | Oconee County, South Carolina | Ocean County, New Jersey |
| Ockendon | Oceana County, Michigan | Oconee County, Georgia |
| Oceanus Procellarum | October Crisis | Ochun |
| Occupation | October 2002 | Ocotillo, California |
| Oceanside, California | Oceano, California | Occidental, California |
| Ocean View, Delaware | Ocala, Florida | Ocean Breeze Park, Florida |
| Ocean City, Florida | Ocoee, Florida | Ocean Ridge, Florida |
| Ocilla, Georgia | Ochlocknee, Georgia | Oconee, Georgia |
| Oconee, Illinois | Ocheyedan, Iowa | Ocean City, Maryland |
| Ocean Pines, Maryland | Ocean Grove, Massachusetts | Ocean Bluff-Brant Rock, Massachusetts |
| Oceola Township, Michigan | Ocqueoc Township, Michigan | Ocean Springs, Mississippi |
