Use this environment variable for Y2K compatibility, when two-digit year values are used.
To set a sliding century window, set a value between 0 and 100. For example, a value of 80 would set a century window of 1931-2030 in 2011, 1932-2031 in 2012, and so on.
To set a fixed century window, set a value between 1000 and 3000. For example, a value of 1973 would set a century window of 1973-2072.
The default is a sliding value of 80 when emulating DFSORT, and a default value of 0 when emulating SYNCSORT. A value of 0 equates to a century window, starting in the current year.
MFJSWINDOW=25
You can use this environment variable instead of the Y2PAST sort option.