Option for moderators to mark themselves as "away"

[Merriweather]

I find that I forgot when my moderators are on vacation for a few days and was looking for a mod where they could somehow mark themselves as away -- perhaps changing their username color or something when they do it. Even better would be if they could enter a date range for when they will be gone and it does it for them automatically -- sets them away and then sets them back at the end.

I haven't seen anything like this...