YSLW - Year Sliding or Fixed Window

This Natural profile parameter specifies the range of years covered by the "year sliding window" or "year fixed window".

Note:
The sliding-window or "year fixed window" mechanism assumes a date with a 2-digit year to be within a "window" of 100 years. Within these 100 years, every 2-digit year setting is uniquely related to a specific century, so that there is no confusion about which century is meant.

Possible settings Normal Setting 0 When you set the parameter to 0, the current century is assumed. No sliding or fixed-window mechanism is used.
Sliding Window 1 - 99 By setting the parameter to a value between 1-99, you determine when the 100-year range begins in the past. The YSLW setting is subtracted from the current year to determine the first year of the window range.

See Example of a Sliding Window.

Fixed Window 1582-2600 By setting the parameter to a value between 1582-2600, you determine the first year of a 100-year range. The upper boundary of the 100-year range is evaluated by adding 99 to the value specified.

See Example of a Fixed Window.

Default setting 0 No sliding or fixed-window mechanism is used.
Dynamic specification yes  
Specification within session no  

The YSLW parameter is evaluated at runtime when an alphanumeric date setting with a 2-digit year component is moved into a date variable. This applies to date settings which are:

  • used with the mathematical function VAL;

  • used with the IS(D) option in a logical condition;

  • read from the stack as input data;

  • or entered in a map as input data.

See also the section Processing of Date Information in the Programming Guide.

Examples of YSLW Parameter

Example of a Sliding Window

If the current year is 2014 and you specify YSLW=40, the sliding window will cover the years 1974 to 2073. A 2-digit year setting nn from 74 to 99 is then interpreted accordingly as 19nn, while a 2-digit year setting nn from 00 to 73 is interpreted as 20nn.

See also the examples under Year Sliding Window - YSLW Parameter and Combinations of DFSTACK and YSLW in the Programming Guide.

Example of a Fixed Window

If you specify YSLW=1985, the fixed window will cover the years 1985 to 2084. A 2-digit year setting nn from 85 to 99 is then interpreted accordingly as 19nn, while a 2-digit year setting nn from 00 to 84 is interpreted as 20nn.