Date value definition
Based on the standards approved by the American National Standards Institute (ANSI), values for the date are typically defined by the year, month, and day elements, ranging from 0001-01-01 through 9999-12-31, delimited by a specific symbol, such as a dot, comma, semicolon, or slash. Thus, we know that the value 2021-05-01 represents 1st May, not 5th January. The format for the Date value representation is YYYY-MM-DD, expressing the year (YYYY), month (MM), and day (DD) elements. To ensure correctness across the centuries, this standard requires a 4-digit year format to be applied precisely.
The available year definition ranges from 0000 to 9999, with 0000 being equal to 1 BCE (Before Common Era) and all subsequent values referring to CE (Common Era). ISO 8601 permits value management lower than 0000 if accepted by the sender and recipient, in which case, an expanded year definition with the + or – sign is present. Thus, +0000 represents 1 BCE while ...
