Usually with rental cars, it is up to a MAX of 30-days, unless stated otherwise... Be careful though as they can drop it without telling you, and you get to pay what is remaining of the bill...
For example, your rent the car for 7 days, insurance cancels your coverage after 4 days but doesn't tell you. yo uhave to pay the remaining 3 days for the car or turn it in... The car rental company WILL come after your for the 3 days as they are a separate company...