@echo off
set day=-3
echo >"%temp%\%~n0.vbs" s=DateAdd("d",%day%,now) : d=weekday(s)
echo>>"%temp%\%~n0.vbs" WScript.Echo year(s)^& right(100+month(s),2)^& right(100+day(s),2)
for /f %%a in ('cscript /nologo "%temp%\%~n0.vbs"') do set "result=%%a"
del "%temp%\%~n0.vbs"
set "YYYY=%result:~0,4%"
set "MM=%result:~4,2%"
set "DD=%result:~6,2%"
set "d=%yyyy%-%mm%-%dd%"
set "d2=%yyyy%%mm%%dd%"

rem echo %d%
rem pause

rem Tento ide, ale zabali vsetko
"C:\Program Files\WinRAR\WinRAR.exe" a -afzip %d%"-diff.zip" "C:\adresar1" "C:\adresar2"

rem Ale tento nejde
"C:\Program Files\WinRAR\WinRAR.exe" a -ta%d2%" -afzip %d%"-diff.zip" "C:\adresar1" "C:\adresar2"