MMdd

MMDD is a calendar date notation that encodes the month and the day of a date, typically in the order month then day. In common practice, it appears as a four-digit string (MMDD) or with separators such as MM/DD or MM-DD. Months and days are usually zero-padded (01–12 and 01–31), though some systems allow single-digit forms like 7/4.

Used primarily in the United States and in some business forms, MMDD appears on documents, forms, and software interfaces that require a concise date representation. It may be used alone when the year is not relevant, or as part of a year-inclusive format such as MMDDYYYY or MM/DD/YYYY. In many contexts, the year is added to disambiguate age, seasonal planning, or historical data.

Ambiguities arise in international communication because many countries use DD/MM or other date orders. Without a year, MMDD can be confused with DDMM in such contexts. For data interchange, ISO 8601's YYYY-MM-DD is recommended to eliminate confusion; when only month and day are needed, specifying locale or including the year can mitigate misinterpretation.

Examples: 0704 represents July 4 in MMDD; 12/31 represents December 31.

History: The MMDD convention reflects US-centric date notation and is widely used in consumer and administrative contexts, but it is not a universal standard. In formal international systems, more explicit formats or the ISO standard are preferred.