中国DOS联盟

@echo off
: 1
set /p d=输入向前推的天数
set nian=%date:~0,4%
set yue=%date:~5,2%
set ri=%date:~8,2%
for %%i in (1 3 5 7 8 10 12) do (if %yue% equ %%i if %ri% gtr 31 set ri=31)
for %%i in (4 6 9 11) do (if %yue% equ %%i if %ri% gtr 30 set ri=30)
for %%i in (2) do (if %yue% equ %%i if %ri% gtr 29 set ri=29)
if %ri% leq 0 set /a %yue%-1
if %yue% leq 0 set /a %nian%-1
set c=%nian%%yue%%ri%
set /a q=%c%-%d%
echo %q%
pause
goto 1
什么地方不对？能不能帮我改下。。。谢谢