how long do u have give people to get out of your rental property due to non payment of rent in illinois??

My renters have never been on time paying their rent since they have moved in. right now they owe me half of last months rent and are 3 days late on this months. they never answer thier phone or return my calls. do i have to give them 30 days to get out, or can i make them leave sooner?? Thank YOU!!