Export Adding 2 Seconds

I am exporting for a TV broadcast that needs to be exactly 28:30, and every time I export it exports at 28:32. I tried setting the out point to 28:28 and it then exports at 28:30, yet I need those last 2 seconds on my timeline. Anyone know why this is happening?

Is Drop Frame relevant here?

Exporting a 24fps project/timeline at 23.976fps could explain this. For a 24fps timeline, there would be about a 2s difference between exporting at 24fps and 23.976fps at 28.5 mins.

I figured it out! I also assumed it was a drop frame issue, yet it actually is a quicktime issue. I'm on a Macbook and I was doing a quick preview of the exported video with the spacebar and it was showing the extra 2 seconds. When I double click on the video and open it, it then shows the correct time.