Zeller公式
:set_week
set TODAY=%date%
REM 日付の分解
set /a h=%TODAY:~0,2%
set /a y=%TODAY:~2,2%
set m1=%TODAY:~5,1%
set m2=%TODAY:~6,1%
if "%m2%" equ "/" (
set /a m=m1
set /a d=%TODAY:~7,2%
) else (
set /a m=m1*10+m2
set /a d=%TODAY:~8,2%
)
if %m%==1 ( set /a y-=1&set /a m+=12 )
if %m%==2 ( set /a y-=1&set /a m+=12 )
REM ツェラーの公式
set /a week_value=( y + (y/4) + (h/4) - 2*h + (13*(m+1)/5) + d ) %% 7
REM 曜日の設定
if %week_value%==0 set WEEK=SAT
if %week_value%==1 set WEEK=SUN
if %week_value%==2 set WEEK=MON
if %week_value%==3 set WEEK=TUE
if %week_value%==4 set WEEK=WED
if %week_value%==5 set WEEK=THU
if %week_value%==6 set WEEK=FRI
exit /b