Need a little help

[MuSuL]

I'm trying to code a little hack to display the top 10 posters for the month. I'm a little stuck on the SQL code. Actually, the dateline is what is the problem

This is the sql statement

SELECT count( * )
as postcount, username, userid
FROM post
where dateline
between startdate
and enddate
GROUP BY userid
ORDER BY postcount DESC
LIMIT 0, 10

It returns no record. I know it's because the date is stored in that millisecond format but I am having problems in finding out how to select it. Can anyone give me a hand?