October 31 is day 304 of the year, or 305 in a leap year, with 61 days remaining after it. It is Halloween. It falls on a Sunday in 2027 and a Tuesday in 2028.
The date carries two of the largest hinges in Western history and one of its more improbable coincidences.
Martin Luther’s Ninety-five Theses reached the Archbishop of Mainz on October 31, 1517, and Mount Rushmore was completed on October 31, 1941 — the same day a German U-boat torpedoed the USS Reuben James off Iceland, the first American warship sunk by hostile action in the Second World War, five weeks before the United States entered it.
Table of Contents
What day of the week is October 31?
October 31 is day 304 in a common year and day 305 in a leap year.
| Year | Day of week |
|---|---|
| 2026 | Saturday |
| 2027 | Sunday |
| 2028 | Tuesday |
| 2029 | Wednesday |
| 2030 | Thursday |
| 2031 | Friday |
| 2032 | Sunday |
| 2033 | Monday |
| 2034 | Tuesday |
| 2035 | Wednesday |
The weekday matters for trick-or-treating. When October 31 falls on a Sunday, as in 2027 and 2032, some municipalities move neighbourhood trick-or-treating to the preceding Saturday.
There is no national rule and the decision is made locally, usually announced in early October.
Observances on October 31
| Observance | Scope | Notes |
|---|---|---|
| Halloween | International | Not a US federal holiday |
| Reformation Day | Protestant Christian | Public holiday in several German states |
| Nevada Day | Nevada | Observed the last Friday in October |
| All Hallows’ Eve | Christian | Vigil of All Saints’ Day, November 1 |
| National Trick or Treat Day | United States | |
| World Cities Day | United Nations |
Nothing closes federally on October 31. Nevada Day is a state holiday but is observed on the last Friday in October rather than on the 31st itself, so the two coincide only in some years.
Since the Energy Policy Act of 2005 moved the end of daylight saving time to the first Sunday in November, Halloween has always fallen while daylight time is still in effect — which puts sunset near 6 p.m. rather than 5 p.m.
Historical events on October 31
475 — Romulus Augustus was proclaimed Western Roman Emperor. He would be deposed the following year, conventionally marking the end of the Western Roman Empire (Wikipedia).
1517 — Martin Luther sent his Ninety-five Theses, denouncing the sale of indulgences, to Albrecht, Archbishop of Mainz. This is generally treated as the start of the Protestant Reformation (Associated Press; Britannica).
1864 — Nevada was admitted to the Union as the 36th state. Congress expedited the admission to secure support for Abraham Lincoln’s re-election, despite the territory having roughly 40,000 inhabitants against the 60,000 normally required. The state motto, “Battle Born,” records the circumstance (History.com; Associated Press).
1922 — Benito Mussolini became prime minister of Italy (Britannica).
1926 — Harry Houdini died in Detroit of peritonitis following a ruptured appendix, twelve days after being struck in the abdomen by a student in Montreal (History.com; Associated Press).
1940 — The Battle of Britain ended, with Germany abandoning its plan to invade the United Kingdom (Wikipedia).
1941 — Work was completed on the Mount Rushmore National Memorial in South Dakota, fourteen years after it began (Britannica; Associated Press).
1941 — The destroyer USS Reuben James was torpedoed by a German U-boat near Iceland with the loss of around 100 sailors — the first US Navy ship sunk by hostile action in the war, more than five weeks before the United States entered it (Associated Press; Wikipedia).
1950 — Earl Lloyd became the first African American to play in an NBA game, in the season opener for the Washington Capitols (History.com).
1984 — Indira Gandhi, prime minister of India, was assassinated by two of her own Sikh bodyguards (Britannica).
Did Luther actually nail the theses to the door?
The image is universal and the evidence is thinner than the story suggests. What is documented is that Luther sent the Ninety-five Theses to Albrecht of Mainz on October 31, 1517, enclosed with a letter.
The nailing to the door of the Castle Church at Wittenberg comes from an account by Philipp Melanchthon, written after Luther’s death, and Melanchthon was not in Wittenberg in 1517. Posting notices on the church door was ordinary academic practice at the time, so the act is plausible — but Britannica frames it as tradition, and the Associated Press qualifies it as occurring “by some accounts.”
The page states both because the distinction between what is recorded and what is traditional is the substance of the question, not a quibble.
Notable births on October 31
| Year | Person | Known for |
|---|---|---|
| 1795 | John Keats | English poet |
| 1887 | Chiang Kai-shek | Chinese political and military leader |
| 1931 | Dan Rather | American journalist |
| 1961 | Peter Jackson | New Zealand film director |
| 2000 | Willow Smith | American singer |
Zodiac sign and birthstone for October 31
October 31 falls under Scorpio, which runs from approximately October 23 to November 21. The date sits well inside the range.
| Value | |
|---|---|
| Zodiac sign | Scorpio |
| Sign dates | About October 23 to November 21 |
| Element | Water |
| Birthstones | Opal and tourmaline |
| Birth flowers | Marigold and cosmos |
October is one of the months with two widely recognised birthstones. Opal is the traditional stone; tourmaline was added as a modern alternate.
How many days until October 31?
The next October 31 falls on a Sunday in 2027. It is day 304 of the year, leaving 61 days remaining after it.
October 31 is the day before All Saints’ Day and, in 2027, a full week before daylight saving time ends on Sunday, November 7.
Frequently asked questions
What day of the week is October 31, 2027?
Sunday. Because daylight saving time does not end until Sunday, November 7 in 2027, sunset falls around 5:55 to 6:05 p.m. across most of the continental United States. Some municipalities move trick-or-treating to Saturday, October 30 when the date lands on a Sunday.
What happened on October 31, 1517?
Martin Luther sent his Ninety-five Theses to the Archbishop of Mainz, an act generally treated as the start of the Protestant Reformation. Whether he also nailed them to the Castle Church door at Wittenberg is traditional rather than documented — the account comes from Melanchthon, written after Luther’s death, and Melanchthon was not there in 1517.
Is October 31 a holiday?
Not federally. Halloween appears nowhere in 5 U.S.C. 6103 and closes nothing in the United States. Reformation Day is a public holiday in several German states, and Nevada Day is a state holiday observed on the last Friday in October rather than on the 31st.
