After completing the post production of the most recent installment of Interludes for the TV show Interludes, I learned a very important difference between network interpreted total run time and actual total run time.  This distinction is the difference between being on time and 8 seconds over in a 60 min program.  This might not make any since to those who don't work with broadcast networks but it was something I had to learn inorder to get my program past TVOne's quality control.   Allow me to explain... TVOne and other networks calculate the length of a program not by adding up all the active  frames as your NLE system does but caluculates each segment beginning and end to the nearest second.  As an example, if the second act of your program begins at 01:12:00;28 and runs to 01:18:01;03 you would caculate the duration to be 00:06:00;05.  Now you could look at this as a 6 minute segment but the networks see it as a duration of 00:06:02;00.  Now that might not seem to be a big difference (only 2 seconds) but if you take the same approach in calculating every segment (TVOne requires 8) it will put your program 16 seconds over the allowed clock.  This will be a sure fire way to get your program rejected by the network.  How does the network caculate segment duration then?  Using the same example, the networks first notes the start of the segment as 01:12:00:00 and the ending as 01:18:02;00.  They take the safe approach of not wanting to "upcut" the start of each segment by moving the start point to the nearest previous second.  Frames are meaningless to them.  The ending timecode is always rounded up to the nearest second.  This also prevents them from "upcutting" the back of the segment.  Even though the program segment is mathmatically 5 frames over 6 minutes it is much more than 5 frames to the network.   

I have known for years that networks round up durations but TVOne takes it a step more.   If you try to make it easy on yourself as you edit and make every segment begin and end on a zero frame, you will not pass QC!  The zero frame is your enemy.  If the segment begins at a zero frames the network will put your start time a full second back and add that second to your duration.  Also, if you end on a zero frame, the network will add an additional second to your program.  They also caculate frame slipage from the tape.  This can be plus or minus a frame and depending on what way it slips it can dramaticly change the ending duration.  


When we submitted the last installment of Interludes (Johnny Gill), my edit was 8 seconds over.  To fix this, I simply put every segment start time at 03 frames and every ending code at  27 frames.  Even calculating for frames slipage, it would insure that the network would round backward and forward to the second I needed them to inorder for my NLE timeline and network time to match.  I did not need to remove 8 seconds from the program but only remove and add 2 frames to each segment!!! It's all about where the segments land on the timeline.   So when my editing software says its 6 minutes, the network will agree.