Statements of the time of day are made in various ways in different countries. To avoid confusion in international communications, the International Organization for Standardization (ISO) established (in 1986) International Standard 8601 for representation of dates and times. The ISO 8601 format for time statements is HH:MM, or HH:MM:SS, where HH is the hour number (00 to 23), MM is the minute number (00 to 59), and SS is the second number (00 to 59, except on those very rare occasions where a "leap second" 60 has been introduced as described under day [2]) . Decimal fractions of the second can be added, as in 07:14:23.625. Colons are specified as the separators in the representation (if separators are used at all; HHMMSS is also acceptable). The times called 1:23 am and 1:23 pm in U.S. practice are represented as 01:23 and 13:23, respectively. Midnight can be represented as 00:00 of the new day or as 24:00 of the day ending. For additional information, see ISO's Date and Time Format FAQ