Query for total duration of problem status of an item

[addyrocker]

Hello guys,

I need help with generating certain outage reports. What I'm trying to do is get the total status problem duration of a particular item of a host for a week or a day kind of like in webfront end of zabbix events.
What I'm looking at is the events table in the database

+---------------+---------------------+------+-----+---------+-------+
| Field         | Type                | Null | Key | Default | Extra |
+---------------+---------------------+------+-----+---------+-------+
| eventid       | bigint(20) unsigned | NO   | PRI | NULL    |       |
| source        | int(11)             | NO   |     | 0       |       |
| object        | int(11)             | NO   | MUL | 0       |       |
| objectid      | bigint(20) unsigned | NO   |     | 0       |       |
| clock         | int(11)             | NO   | MUL | 0       |       |
| value         | int(11)             | NO   |     | 0       |       |
| acknowledged  | int(11)             | NO   |     | 0       |       |
| ns            | int(11)             | NO   |     | 0       |       |
| value_changed | int(11)             | NO   |     | 0       |       |
+---------------+---------------------+------+-----+---------+-------+

I'm having trouble understanding what the ns field is, I know its nanoseconds something, is it the field of the duration of the problem like in the frontend events?, If I run the below query which is of a particular item which had problem status

select eventid, objectid, FROM_UNIXTIME(clock), ns  from events where objectid=16801 and value=1;
+---------+----------+----------------------+-----------+
| eventid | objectid | FROM_UNIXTIME(clock) | ns        |
+---------+----------+----------------------+-----------+
|   17027 |    16801 | 2012-11-08 01:08:08  | 475741590 |
|   17046 |    16801 | 2012-11-08 01:12:26  | 526949770 |
|   17048 |    16801 | 2012-11-08 01:26:00  | 411519269 |
|   17066 |    16801 | 2012-11-08 01:31:49  | 428655906 |
+---------+----------+----------------------+-----------+

What I would like to get is the total problem duration, summed, of a particular objectid in this case 16801, I hope I'm making sense; value=1 indicates its a Status=Problem
I hope someone can point me out in the right direction and if this can be accomplished through some other way?
Help would be greatly appreciated!