@echo off & setlocal enableextensions disabledelayedexpansion
  if "%~3"=="" (
    echo Usage: %~0 DD MM YYYY
    echo No leading zeros!
    goto :EOF)
  ::
  :: Get the date
  set day=%~1
  set month=%~2
  set year=%~3
  ::
  :: Call the day ordinal number subroutine
  call :JDdayNumber %day% %month% %year% DayOrdinalNumber
  ::
  :: Display the result
  echo %day%.%month%.%year% Day ordinal number %DayOrdinalNumber%
  endlocal & goto :EOF
  ::
  :: ============================================================
  :: Subroutine: Calculate a day's ordinal number within the year
  :JDdayNumber day month year return_
  setlocal enableextensions enabledelayedexpansion
  if %2 LEQ 2 (
    set /a f=%1-1+31*^(%2-1^)
    ) else (
    set /a a=%3
    set /a b=!a!/4-!a!/100+!a!/400
    set /a c=^(!a!-1^)/4-^(!a!-1^)/100+^(!a!-1^)/400
    set /a s=!b!-!c!
    set /a f=%1+^(153*^(%2-3^)+2^)/5+58+!s!
    )
  set /a return_=%f%+1
  endlocal & set "%4=%return_%" & goto :EOF

::
:: ============================================================
:: Subroutine: Calculate a day's ordinal number within the year
:: Based on a posting by Herbert Kleebauer
:JDdayNumber d m y w
setlocal enableextensions disabledelayedexpansion
set /a w= %1 +(!(%3 %% 4)-!(%3 %% 100)+!(%3 %% 400))*(!((%2-3)^&16))
set /a w=(%w%+(%2-1)*30+2*(!((%2-7)^&16))-1+((65611044^>^>(2*%2))^&3))
endlocal & set "%4=%w%" & goto :EOF