II_DATE_CENTURY_BOUNDARY determines the inferred century for a date that is missing the century on input. It can be set to an integer value in the range of 0 < n < =100. If this environment variable is not set in the user’s environment or if it is set to 0 or 100, the current century is used.

The century is determined by the following calculation:

For example, if II_DATE_CENTURY_BOUNDARY is 50 and the current year is 1999, an input date of 3/17/51 is treated as March 17, 1951, but a date of 03/17/49 is treated as March 17, 2049.

If the user enters the full four digits for the year into a four-digit year field in the application, the year is accepted as entered, regardless of the II_DATE_CENTURY_BOUNDARY setting.