Daymonth

Daymonth is a term used in computing and data formats to refer to the day and month components of a calendar date, with the year omitted. It functions as a building block within date representations rather than a standalone, universal standard.

In practice, daymonth may appear as numeric pairs such as ddMM or DD-MM, with years left out, or as textual forms like 25 July. Because the year is not specified, the same daymonth can describe dates in different years depending on context, which can affect interpretation across systems or locales.

Daymonth is common in local date formats in many regions that read the day before the month, including much of Europe and parts of Asia and Latin America. It contrasts with year-first formats (YYYY-MM-DD) used in ISO 8601 and in many technical contexts, where the year is given first and the date is unambiguous across years.

Use of daymonth is practical for recurring annual events, birthdays, anniversaries, or seasonally tied data. However, omitting the year can lead to ambiguity across years or in international data exchange, so including the year is advisable when precision is required.

In databases and programming, daymonth might appear as a date part, a format specifier, or a locale-dependent display. See also date formats, DMY, ISO 8601, and calendars.