bug on the where sql where syndax ??

HI,
I HAVE TRIED EVERUTHING TO SHOW 3 NEXT DAYS ACTIONS

I M PUTTING ON THE WERE SQL SYNDAX
DATEDIFF( a.field_6, curdate()) >0 && DATEDIFF( a.field_6, curdate()) <4
AND WHEN I M SAVING I M GETTING
DATEDIFF( a.field_6, curdate()) >0 && DATEDIFF( a.field_6, curdate())


why its eating the < sign ???

thank you