...
12:58:03 User 1 sign on
12:59:03 User 1 sign off
12:59:25 User 2 sign on
12:59:50 User 3 sign on
13:00:00 REPORT: online: (2-12:59:25,3-12:59:50)
13:02:23 User 4 sign on
13:03:12 User 3 sign off
13:04:23 User 4 sign off
13:04:34 User 5 sign on
13:06:52 User 5 sign off 
...

##</code><code>##

Users online: 2
User 2 (since 12:59:25)
User 5 (since 13:04:34)