My last flight of the year will be JFK-TLV. I will be departing on Dec 31 and arriving on Jan 1.

Will the MQMs I earn be credited to 2013 (which will bring me to Gold) or to 2014 (which, together with the rollover MQMS, make me Silver for that year)?

Yeah.

Huh? Wrong answer. The MQM's will not be credited to both years, sorry. Wishful thinking!

My MQM's are always credited based on the date my flight departs. So I would assume yours would be the same - 2013 in your case. If you had a connecting flight TLV-XXX, then that flight on 1 January would be credited to 2014.

If you want to avoid getting GM, you have to credit the miles for that trip to another airline.

It has been my experience that MQMs are based on the route you actually fly. When I've changed flights last minute (to, say a trip with two legs instead of one) then the miles credit to my account a day or two later based on the trip I actually ended up taking and not the one I originally booked. With that in mind, I'd say your miles must post in 2014 after the flight(s) complete. They'll be added to the rollover miles when the rollover is processed (a week or two into the year IIRC) to establish your new status.

If you're that close to a threshold I'd look for an extra miles run, credit card offer, or purchase of MQMs to push you over the top. You'll be gold for all of 2014. Safe travels.

It would have to be a heck of a mile run. My JFK-TLV flight is earning me 8,516 MQMs.

In fact, I am doing a mini-mile run already. I was originally planning on flying JFK-LAS, but changed it to LGA-ATL-LAS -- it is the same cost but put me just over the top for Gold (if I am credited in 2013 for the flight back to TLV) or Silver (if it goes towards 2014).

It didn't work out too badly. I am paying $3147 for the itinerary, used two SWUs which got me upgraded TLV-JFK, ATL-LAS, LAS-ATL, ATL-JFK, and JFK-TLV. I am in EC LGA-ATL, but it is a 2 1/2 hour flight so it does not really bother me and, as a PM flying on a B fare upgraded with SWUS, the odds are good that I will be upgraded even for that one segment.

My understanding is that each segment credits for the year of its scheduled departure, so that even if the flight departs late, it would still count for 2013. I would expect the same for ORC if you're rebooked in IROPs but YMMV. (Not requesting ORC would probably mean that the rebooking would credit as 2014, assuming that the new flight is scheduled to depart after midnight.) Direct flights would all credit based on the first departure, so that even after an aircraft change, the flights would credit to 2013. However, connecting flights that are scheduled to depart after midnight would count as 2014.

Remember that DL supposedly doesn't allow you to credit different flights of a single itinerary to different FF programs, nor can you change (or delete?) the FF number after departure of the first flight of an itinerary.

Enjoy New Year's Day in Vegas.

I wouldn't think of changing the number. On one hand, I might make Gold -- on the other hand, I will be Silver until March 2015. If I don't earn all the MQMs, I will both remain at Silver for 2013 and not reach it the following year.

Will definitely count for 2013 based on my experience. Flew to HKG on NYE a few years ago with the RT in the new year and the miles were posted for the year of departure.