how to get End of month for reporting

Dear Experts , 

i'm doing a report for incidents  opened from the begining of the current month till the end of the current month 

i now that there are a function now named startofmonth() . is there another function that i can get the date of end the current month 

i tried endofmonth()  and startofmonth() 30 00:00:00 and it did not work 

any ideas ?