
Natural for OpenVMS	Version 6.3.12 for OpenVMS	SEARCH CONTENTS \| PDF BOOKS \| HOME UP PREV NEXT

— Parameter Reference —

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. Example: If the current year is 2002 and you specify `YSLW=40`, the sliding window will cover the years 1962 to 2061. A 2-digit year setting `nn` from `62` to `99` is then interpreted accordingly as `19nn`, while a 2-digit year setting `nn` from `00` to `61` is interpreted as `20nn`.
	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. Example: 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`.
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 data 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.

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