Both the British Standards Institute (BSI) and the International Organization for Standardization (ISO) publications describe a common format for the standard representation of date, time of day, and combinations of dates. For example, the standard notation for the date is the sequence YYYY-MM-DD or YY-MM-DD.

The relevant standards are:

• BS EN 28601 : 1992
  ’Specification for representation of dates and times in information interchange'
  (NB. BS EN 28601 replaced BS 7151 : 1989)
• ISO 8601 : 2004
  'Data elements and interchange formats - information interchange - Representation of dates and times'