Anytime you cross the combat zone as defined by the COMAFFOR, log combat time. If you refueled combat aircraft outside the combat zone, log combat support. If you refueled combat aircraft inside the combat zone, log combat time. But seriously, who gives a crap? If Delta, Southwest, Cathay, or Qantas, or Fedex cared, I would, but they don't. So who cares? And if you do, you are a tool.
I don't make the rules, just repeating them. AFI 11-401 3.3.6.
Lots of tanker dudes have hundreds and even a thousand or more of combat time since 2001. Even more embarrassing, some of us have "V" devices for our time spent in the combat zone. I have two and I didn't put in for it. They were awarded to me and showed up on my rack in MPF. Ridiculous, yes. Personally I think it is a slap to the face for our troops on the ground in combat arms. Worse, I know a crew who transited an area of friendly fire (unbeknownst to them) and they put in medals for being shot at despite me and the DO showing the CC exactly on the map where they were, and the ATO about the friendly fire exercises. They wrongly transited a restricted area and AWACs let them do it and thus they were surprised by the tracers flying past them. STILL, they were awarded medals. Don't get me started on this crap .. my blood pressure is high enough as it is and there's so much BS about this type of stuff it isn't funny.