Dias has nailed it again but please run the following and post the outcome.
@echo off
cls
set today=%date:~-4%%date:~4,2%%date:~7,2%
echo wscript.echo (date-1)>yesterday.vbs
for /f "delims==" %%D in ('cscript //nologo yesterday.vbs') do (
set yesterdate=%%D
)
echo %yesterdate:~-4%
echo %yesterdate:~4,2%
echo %yesterdate:~7,2%
echo.
set yester=%yesterdate:~-4%%yesterdate:~4,2%%yesterdate:~7,2%
del yesterday.vbs
echo Todays date is %today%
echo Yesterday's date was %yester%
Thanks