How do i assign Integers only and not real numbers?

Hi all, I have a line of code that assigns a new year number: - $years = $years + ( $themonth / 12 ); but sometimes $years == 1998.0833333333 or $year == 2002.75 etc... I cant find anything like a round() or floor() function in PHP so that year would be 1998 or 2002 only. Does anyone know what function would do this? Sorry if I`m wasting your time if its a really obvious one! thanks in advance, Tom