A easier question would be how old is the rest of the brood in the hive? If you don't have new eggs and uncapped brood that queen cell is likely +9 days old.
I see no bees and all the brood around the cell has emerged. Since queen cells are the shortest gestation time (16 days from egg to queen) I'm guessing it's not going to emerge.
I cannot tell for sure how old it is from the picture. Here are couple of observations that may help you:
By the way the bottom is getting thinned, it is ready to emmerge if it is viable.
I don't see much capped brood around it. According to bee math here http://www.bushfarms.com/beesmath.htm, the queens emmerge faster than workers and drones. So if everything around that cell emmerged already, then the cell is probably not viable.
When was the last time you checked on this hive before finding the cell? How is the hive population looking like?
Hmm...interesting thoughts. The reason there are no bees is I brushed them off to photograph the cell
All the brood except for one cell in this hive was capped as of yesterday.
The hive population is okay, but have been queenless for over a week as this was a combine, and I am almost positive they killed the laying queen and maybe the other queen too. I thought the one hive was queen less, but actually it wa not, so at least one or maybe both queens died/were murdered lol
I would add one more frame of young larva and eggs just for insurance. Then recheck the hive in about 5 days and you should either have a new virgin or new queen cells on the frame you added. Either way it should help you figure out what stage the hive is in.
Like Marince has said the bottom of the cell has been thinned in preparation of queen emergence.
If it's viable, which I expect it will be or the bees would have torn it down by now, I would expect it to hatch in 24 to 36 hours