How can I grouping an unix time per day?

I have a table like this: // requests +----+----------+-------------+ | id | id_user | unix_time | +----+----------+-------------+ | 1 | 2353 | 1339412843 | | 2 | 2353 | 1339412864 | | 3 | 5462 | 1339412894 | | 4 | 3422 | 1339412899 | | 5 | 3422 | 1339412906 | | 6 | 2353 | 1339412906 | | 7 | 7785 | 1339412951 | | 8 | 2353 | 1339413640 | | 9 | 5462 | 1339413621 | | 10 | 5462 | 1339414490 | | 11 | 2353 | 1339414923 | | 12 | 2353 | 1339419901 | | 13 | 8007 | 1339424860 | | 14 | 7785 | 1339424822 | | 15 | 2353 | 1339424902 | +----+----------+-------------+ I want to grouping unix_time column based on separated days. Actually I'm trying to make this for an specific user: As you see I need tow numbers for an user: the number of all days which there is a foot print of the user into requests table the number of biggest consecutive days How can I do that? Actually I can use WHERE id_user = :id to select user's rows. And I can calculate the number of days by SUM(). And by using MAX() I can calculate the biggest consecutive range. Just I need to grouping those unix times.