Something that can say how long the current map has been going for?

Is there a way to make something say how long you have been in the current map for, how long the actual thing has been running for would be just as good as well (like, if it counted the time that you have been in 3 maps for because you used toggle_mapchange or something. I dont specifically want it to do this but it wouldn't matter if it did.) So I could have a button that made something say the time you have been playing on the map for.