Click and drag on sequence shows time duration of dragged area

I think it would be great to have the simple implementation of time indication when you click and drag in the timeline and the white rectangle appears. 

This would be a simple, quick, easily accessable feature / tool that could be used to quickly check the duration of a particular section (as dragged accross the timeline). Which is something I need to do more and more in todays social media generation where ads and other quick cutdowns need to be very specific short durations (45sec, 30sec, 5 sec etc). Looking up at the inscribed timing on the timeline is not enough to guage how long a particular chunk of somoenes audio is when it's all cut up. 

In my mind when you click and drag down the timeline, next to the cursor you would see a selection duration indicator "xx frames, 4:02sec" or simliar.