中国DOS联盟

@echo off
setlocal enabledelayedexpansion

:Main
set day=%date%
set days=0
::echo.&echo.


:: 提取日期
set /a sy=%date:~0,4%,sm=%date:~5,2%,sd=%date:~8,2%

::指定天数
set /a sd-=2

if %sd% leq 0 call :count

::echo.&echo.
set sm=0%sm%
set sd=0%sd%
set target=%sy%%sm:~-2%%sd:~-2%
::删除文件
for /D %%i in (*) do  if %target% gtr %%i  rmdir /s /q %%i
pause>nul
goto Main

:count
set /a sm-=1
if !sm! equ 0 set /a sm=12, sy-=1
call :days
set /a sd+=days
if %sd% leq 0 goto count
goto :eof

:days
:: 获取指定月份的总天数
set /a leap="^!(sy %% 4) & ^!(^!(sy %% 100)) | ^!(sy %% 400)"
set /a max=28+leap
set num=0
set str=31 %max% 31 30 31 30 31 31 30 31 30 31
for %%i in (%str%) do (
    set /a num+=1
    if %sm% equ !num! set days=%%i&goto :eof
)
goto :eof