Batch file IF %time% not working

Try this:

SET "ADJUSTEDTIME=%TIME: =0%"
IF "%ADJUSTEDTIME:~0,5%" GEQ "19:58" GOTO :SHUTDOWN  
IF "%ADJUSTEDTIME:~0,5%" LSS "08:58" GOTO :SHUTDOWN  
GOTO :EOF  
:SHUTDOWN  
MSG * "Your device has not been authorised for use at this time and will now shutdown."  
SHUTDOWN -s -t 120