How To Display Turn Around Time For Jobs?

I’m trying to figure out a way I can display my current turnaround time for a service I offer.

I’d like to have a nice visible number in the header that says something like “Current Turnaround Time Is X Days”.

I don’t need it to automatically figure out anything, I don’t mind manually entering a number, but it would be nice to be able to do that in the dashboard rather than having to dig into the theme.

Anyone know of a plugin to do this? I’m not much of a PHP guru, but if it’s a simple task, I might be able to figure it out.

Any thoughts would be much appreciated.

Thanks!
– Michael