Oh, I'm perfectly aware of what aerobatics are...I've just never heard of "aerobatic time". Never seen that column in a logbook before.
How do you log it? Is it only the time which you are greater than 30 degrees of pitch or 60 degrees of bank? Do you have to be executing an aerobaatic maneuver to log it, or is unusual attitude training included? Do you have to be wearing a chute and in an appropriate category aircraft, or can you roll your Citation and log "aerobatic time"? Do you log it in tenths, or seconds?