Definition

1. Noun:
   • The extra day in a leap year: "bissextile day" is the specific name for the additional day inserted into the calendar during a leap year, which is February 29th.

Usage

• The term "bissextile day" is a formal, technical, and historical term for February 29. It is rarely used in everyday modern English, where "leap day" is the common term. It is primarily found in historical, legal, or calendrical contexts.

Examples

• Noun:
  • The contract's term is calculated to include the bissextile day.
  • In the Julian calendar, the bissextile day was inserted after February 24th.

Advanced Usage

• Historical Context: The term originates from the Roman calendar, where the extra day was inserted after the "sixth day before the Calends of March" (), hence "bissextile" (twice-sixth).

Variants and Related Words

• Leap day (n): The common modern term for February 29 in a leap year.
• Intercalary day (n): A more general technical term for a day inserted into a calendar to synchronize it with the solar year.

Synonyms

• Leap day: The standard, contemporary synonym.
• February 29: The direct calendrical reference.

Noun

1. the name of the day that is added during a leap year