Hey,
According to what you said, you have a field dateofevent, and you are using a mysql_fetch_array.
The problem/question is dateofevent is probably stored as a string/date in the database.
If that is the case, $row[dateofevent] will contain that specifc date after every loop. So within the mysql_fetch_array() loop you also have to include.
SELECT EXTRACT(MONTH FROM '$row[dateofevent]');
and obtain the month since it turns into an integer and put it into some variale called $EvenOdd. then make if statements
if ($EvenOdd%2 == 0){
.
.
.
}
else{
.
.
}