This DataType defines a value which is the string representation of a time. It conforms to lexical rules in ISO 8601-2000.
Table 19 - TimeString Definition
Subtype of the String defined in OPC 10000-3
ISO 8601 uses the 24-hour clock system. The basic format is [hh][mm][ss] and the extended format is [hh]:[mm]:[ss].
[hh] refers to a zero-padded hour between 00 and 24 (where 24 is only used to notate midnight at the end of a calendar day). [mm] refers to a zero-padded minute between 00 and 59. [ss] refers to a zero-padded second between 00 and 60 (where 60 is only used to notate an added leap second). So a time might appear as either “134730” in the basic format or “13:47:30” in the extended format.
It is also acceptable to omit lower order time elements for reduced accuracy: [hh]:[mm], [hh][mm] and [hh] are all used.
Midnight is a special case and can be referred to as both “00:00” and “24:00”. The notation “00:00” is used at the beginning of a calendar day and is the more frequently used. At the end of a day use “24:00”