Overview

A common year beginning on Tuesday is a 365‑day year in which January 1 falls on a Tuesday. In calendar notation this configuration is sometimes identified by its dominical letter, F, and it determines the weekday for every date in that year. The term "common year" distinguishes it from a leap year, which has 366 days. The pattern of weekday alignments that follows from a Tuesday start repeats according to the long-term cycle of the calendar system in use.

Calendar characteristics

Because the year is not a leap year, February has 28 days and months shift weekdays in a fixed way. For a common year that starts on Tuesday, the first day of each month falls on these weekdays:

  • January 1 — Tuesday
  • February 1 — Friday
  • March 1 — Friday
  • April 1 — Monday
  • May 1 — Wednesday
  • June 1 — Saturday
  • July 1 — Monday
  • August 1 — Thursday
  • September 1 — Sunday
  • October 1 — Tuesday
  • November 1 — Friday
  • December 1 — Sunday

From these starting weekdays it follows that Friday the 13th occurs twice in such a year: in September and in December. This pair of Friday the 13ths is shared with certain other calendar starting patterns.

Examples and calendar families

Instances of this pattern can be found in both the Gregorian and Julian systems. Notable Gregorian examples include 1974, 1985, 1991, 2002, 2013, 2019, and 2030. In the Julian calendar the same weekday alignment applies to years such as 2014 and 2025. For general reference see a typical calendar description of a common year starting on Tuesday and background on the Julian calendar.

Holidays and notable dates

The weekday assignments influence the observance dates of holidays that fall on fixed dates or on particular weekdays. For example, in a common year that begins on Tuesday:

  • Martin Luther King Jr. Day (third Monday in January) falls on January 21.
  • Valentine's Day (February 14) occurs on a Thursday.
  • Presidents' Day (third Monday in February) falls on February 18.
  • Memorial Day (last Monday in May) is observed on May 27.
  • Independence Day (July 4) is on a Thursday.
  • Labor Day (first Monday in September) falls on September 2.
  • Columbus Day (second Monday in October) falls on October 14, its latest possible date.
  • Thanksgiving (fourth Thursday in November) falls on November 28, also the latest possible date.
  • Christmas Day (December 25) occurs on a Wednesday.

These examples use the U.S. pattern of weekday‑based federal observances; other countries and religions follow different rules and can be checked against the month‑start table above.

Cycles, relations and distinctions

Calendar start‑day patterns repeat according to the underlying leap‑year rules of the calendar system. In the Gregorian calendar the full sequence of date‑to‑weekday mappings repeats every 400 years; in the Julian calendar it repeats every 28 years. A common year beginning on Tuesday is one of a small set of common‑year types that produce two occurrences of Friday the 13th. It shares the September and December Friday the 13ths with some leap‑year and other common‑year configurations — for example, a leap year starting on Monday displays the same pair of months with Friday the 13ths. Related common‑year patterns include a common year starting on Sunday and a common year starting on Monday, which have their own characteristic distributions of weekdays and 13ths.

Because the term "leap year" is often contrasted with a common year, references frequently point readers to explanations of a leap year and how adding a February 29 shifts subsequent month‑start weekdays in the following year.

For practical use, the month‑start table and holiday examples above let anyone determine the weekday of any date in a common year that begins on Tuesday without consulting a full printed calendar.