In 2 cases, improve labels in web interface

I am using firmware 8.1.1 RC2 on a B20x.

At AP tab → wireless client > Wireless Clients section
there is a “duration” field that looks like 99:99:99
What are these numbers? days? hours? minutes? seconds?

In the client details display (shown below - click on the small graph for one client) there is a “Rate” field that is given in “M”. What is M? This display also has a “Duration” field that could use a better label.