Calculate total hours per day based on "TIME_IN" data in one row and "TIME_OUT" data on the next row

I need to calculate the actual time spent in the office per day. I have seen several examples online, but they all have TIME_IN and TIME_OUT in the same row. My application puts entries into a new row each time an "enter" or "exit" is recorded by the tracking device. I am able to calculate overall time per day for a "normal" day with the following query: use timelog; mysql> SELECT TIMEDIFF(MAX(date_time), MIN(date_time)) FROM timelog WHERE day_of_month="11"; +------------------------------------------+ | TIMEDIFF(MAX(date_time), MIN(date_time)) | +------------------------------------------+ | 09:06:00 | +------------------------------------------+ 1 row in set (0.00 sec) The data for all IN/OUT on the 11th: mysql> SELECT status,date_time FROM timelog WHERE day_of_month="11"; +--------+---------------------+ | status | date_time | +--------+---------------------+ | IN | 2017-04-11 08:39:00 | | OUT | 2017-04-11 09:42:00 | | IN | 2017-04-11 10:03:00 | | OUT | 2017-04-11 10:38:00 | | IN | 2017-04-11 10:43:00 | | OUT | 2017-04-11 12:09:00 | | IN | 2017-04-11 13:20:00 | | OUT | 2017-04-11 13:24:00 | | IN | 2017-04-11 13:26:00 | | OUT | 2017-04-11 14:06:00 | | IN | 2017-04-11 14:13:00 | | OUT | 2017-04-11 17:45:00 | +--------+---------------------+ Table: timelog Description: mysql> desc timelog; +--------------+----------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +--------------+----------+------+-----+---------+-------+ | status | char(3) | NO | | NULL | | | date_time | datetime | YES | | NULL | | | day_of_week | char(9) | YES | | NULL | | | month | char(10) | YES | | NULL | | | day_of_month | int(2) | YES | | NULL | | | year | int(4) | NO | | NULL | | | hour | int(2) | YES | | NULL | | | minute | int(2) | YES | | NULL | | | time_of_day | time | YES | | NULL | | | SSID | char(15) | YES | | NULL | | +--------------+----------+------+-----+---------+-------+ All Data for the 11th: mysql> SELECT * FROM timelog WHERE day_of_month="11"; +--------+---------------------+-------------+-------+--------------+------+------+--------+-------------+----------------+ | status | date_time | day_of_week | month | day_of_month | year | hour | minute | time_of_day | SSID | +--------+---------------------+-------------+-------+--------------+------+------+--------+-------------+----------------+ |IN | 2017-04-11 08:39:00 | Tuesday | April | 11 | 2017 | 8 | 39 | 08:39:00 | CGP Financial |OUT | 2017-04-11 09:42:00 | Tuesday | April | 11 | 2017 | 9 | 42 | 09:42:00 | CGP Financial |IN | 2017-04-11 10:03:00 | Tuesday | April | 11 | 2017 | 10 | 3 | 10:03:00 | CGP Financial |OUT | 2017-04-11 10:38:00 | Tuesday | April | 11 | 2017 | 10 | 38 | 10:38:00 | CGP Financial |IN | 2017-04-11 10:43:00 | Tuesday | April | 11 | 2017 | 10 | 43 | 10:43:00 | CGP Financial |OUT | 2017-04-11 12:09:00 | Tuesday | April | 11 | 2017 | 12 | 9 | 12:09:00 | CGP Financial |IN | 2017-04-11 13:20:00 | Tuesday | April | 11 | 2017 | 13 | 20 | 13:20:00 | CGP Financial |OUT | 2017-04-11 13:24:00 | Tuesday | April | 11 | 2017 | 13 | 24 | 13:24:00 | CGP Financial |IN | 2017-04-11 13:26:00 | Tuesday | April | 11 | 2017 | 13 | 26 | 13:26:00 | CGP Financial |OUT | 2017-04-11 14:06:00 | Tuesday | April | 11 | 2017 | 14 | 6 | 14:06:00 | CGP Financial |IN | 2017-04-11 14:13:00 | Tuesday | April | 11 | 2017 | 14 | 13 | 14:13:00 | CGP Financial |OUT | 2017-04-11 17:45:00 | Tuesday | April | 11 | 2017 | 17 | 45 | 17:45:00 | CGP Financial +--------+---------------------+-------------+-------+--------------+------+------+--------+-------------+----------------+ Now for my question(s)... :-) How can I best calculate actual time spent in the office based on the time between each IN and OUT? I'd like to be able to mark the time between say "09:42" and "10:03" as time not worked, and the time between "10:03" and "10:38" as worked, and so on. I have tried negating all "IN" times except for the first of the day, and adding, but that didn't seem to work. Can someone help me craft a SQL statement (I am by no means even a novice) that will step through each day's IN/OUT timestamps and calculate "actual" time spent in the office? Since I am asking for the moon, I might as well ask for Mars too. As I am subject to on-call, it is not uncommon for me to work well past midnight, or as in the case of this morning, be called int the office from 01:00 to 02:45, so I'd like to be able to factor "past midnight" and "came in early, went home, came back in at 08:00" into the equation as well. If you need more information, or clarification on anything I have posted, please let me know. Your help is very much appreciated. Bryan