Set the DOS system date.
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 Syntax

        GT_SetDate(<dDate>) --> lSetOk

 Arguments:

      <dDate> is a date parameter.

 Returns:

      If the date was set ok, GT_SetDate() returns true (.T.), if not
      it returns false (.F.).

 Description:

      GT_SetDate() can be used to set the DOS system date to a new
      value.

 Examples:

      // Set the DOS system date forward one week.

      ? GT_SetDate(date()+7)

 Source: SETDATE.C

 Author:  Dave Pearson