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DATE.CONVERT (DC)
Restrictions
The following restrictions apply to the DATE.CONVERT; command:
$ The handling of signed numerics in Group items by the DATE.CONVERT; command
varies, depending on the compiler implementation. If you use numeric items within a
Group for handling dates, they should be unsigned.
$ There is a limit of 999999 days conversion on relative day number, starting from 1
January of your base year.
$ Numeric inputs to the DATE.CONVERT; cannot be more than 23 characters in length.
Use of GLB.BASE and GLB.CENTURY
The conversion is based upon a base date defined by the System Data items GLB.BASE,
GLB.CENTURY, and GLB.CENTURY-START.
How GLB.BASE is used
GLB.BASE is used in the following ways:
$ GLB.BASE is set on your Primary Specification Options screen, when defining your
LINC Specification. The base year defaults to 1957. The valid range is 1 through 9999.
$ The relative day number of January 1 of the base year is 0. The relative day number
field is a six-digit numeric field.
$ Dates prior to the base year are invalid. However, as described in "Deducing the
Century for Six Digit Dates", the value of GLB.CENTURY may be adjusted
automatically (if the value of GLB.CENTURY is zero or is the same century as
GLB.BASE) to ensure that dates are valid. See also ‘‘Invalid Input Dates’’, later in this
section.
$ You can define the working range of dates (of 100 years) for your LINC System by
using the System Data item, GLB.CENTURY-START, and by using the Supervisor
command SCENTURY. The working range is used to interpret six digits dates, as
described in "Deducing the Century for Six Digit Dates".
Deducing the Century for Six Digit Dates
The value of GLB.CENTURY can be set before the DATE.CONVERT; command, if your
input date does not contain the century (it is a six digit date). This is required if the century
of the input date is different from the LINC default century.
When GLB.CENTURY is zero or is the same century as GLB.CENTURY-START, date
conversion sets GLB.CENTURY, as follows:
$ If the year is equal to or greater than GLB.CENTURY-START year, then
GLB.CENTURY is not set.
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