Source code for leapyear.bat

@ECHO OFF

:: Windows NT 4 and later only

IF NOT "%OS%"=="Windows_NT" GOTO Syntax

SETLOCAL

:: Use current year as default

IF [%1]==[] GOTO ThisYear

:: Only 1 parameter allowed

IF NOT [%2]==[] GOTO Syntax

:: Check for ?

ECHO.%1 | FIND "?" >NUL

IF NOT ERRORLEVEL 1 GOTO Syntax

:: Check if parameter is a number

IF 1%1 LSS 2 GOTO Syntax

:: Check if the number is within range

IF 1%1 LSS 10 GOTO Syntax

IF 1%1 GTR 19999 GOTO Syntax

:: OK, continue

SET yy=%1

GOTO Calculate

:ThisYear

:: Code to extract day, month and year by Simon Sheppard

:: http://www.ss64.com

FOR /f "tokens=2-4 skip=1 delims=(/-)" %%G IN ('ECHO.^|DATE') DO (

	FOR /f "tokens=2 delims= " %%A IN ('DATE /T') DO (

		SET v_first=%%G

		SET v_second=%%H

		SET v_third=%%I

		SET v_all=%%A

	)

)

SET %v_first%=%v_all:~0,2%

SET %v_second%=%v_all:~3,2%

SET %v_third%=%v_all:~6,4%

:Calculate

:: Default to not a leap year

SET LeapYear=0

:: If year is a multiple of 4 then it is a leap year ...

SET /A test = %yy% / 4

SET /A test = %test% * 4

IF %test% EQU %yy% SET LeapYear=1

:: ... except if it is a multiple of 100 ...

SET /A test = %yy% / 100

SET /A test = %test% * 100

IF %test% EQU %yy% SET LeapYear=0

:: ... unless it is a multiple of 400!

SET /A test = %yy% / 400

SET /A test = %test% * 400

IF %test% EQU %yy% SET LeapYear=1

:: Display the result

SET is=IS

IF %LeapYear%==0 SET is=is NOT

ECHO %yy% %is% a leap year

:: Done

ENDLOCAL

GOTO End

:Syntax

ECHO.

ECHO LeapYear.bat, Version 1.01 for Windows NT 4 / 2000 / XP

ECHO Check if the specified year is a leap year or not.

ECHO.

ECHO Usage:  LEAPYEAR  [ year ]

ECHO Where:  "year" is a year between 0 and 9999.

ECHO         If no year is specified, the current year is assumed.

ECHO.

ECHO Written by Rob van der Woude

ECHO http://www.robvanderwoude.com

ECHO.

ECHO Code to extract the current year written by Simon Sheppard

ECHO http://www.ss64.com

:End