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DateSerial# returns a serial number that represents the date of the
arguments.
 
DateSerial# (year%, month%, day%)
    ■ The year% values 0-178 can be used for the years 1900-2078. For all
      other years, use the complete 4-digit year (for example, 1800).
    ■ Arguments outside of the ranges shown on the Syntax screen are
      evaluated to calculate a valid date. For example:
 
        TheDate# = DateSerial#(89, 13, 1)
 
      The month% argument of 13 evaluates to the first month of the next
      year: January 1, 1990.
    ■ Values that equate to a serial number outside of the range of
      -53688 to 65380 produce the error message, "Illegal function call."
      This translates to an actual date range of January 1, 1753 to
      December 31, 2078 inclusive.
    ■ You can use negative numbers as arguments. For example, to find the
      serial number for the date one week before 9/1/89, you could use:
 
        DateSerial#(89,9,1-7)
 
Usage Note
    ■ For information on serial numbers, see ◄Serial Numbers►.
 
Important
    ■ To use DateSerial# in the QBX environment, use the DTFMTER.QLB
      Quick library. To use DateSerial# outside the QBX environment, link
      your program with the appropriate DTFMTxx.LIB file. Depending on
      the compiler options you chose when you installed BASIC, one or
      more of the following files will be available:
 
           Filename         Compiler options
           ════════════     ═════════════════════════════════════════════
           DTFMTER.LIB      80x87 or emulator math; DOS or OS/2 real mode
           DTFMTAR.LIB      Alternate math; DOS or OS/2 real mode
           DTFMTEP.LIB      80x87 or emulator math, OS/2 protected mode
           DTFMTAP.LIB      Alternate math; OS/2 protected mode
 
    ■ The DATIM.BI header file contains the necessary function
      declarations for DateSerial#.
    ■ For more information on using libraries, see "Creating and Using
      Quick Libraries" and "Using LINK and LIB" in the BASIC Programmer's
      Guide.