When going for my annual review the surgery asks you to fast for 14 hours. Different web sites give different times from 8 to 12 hours never 14.
A couple of years ago I said that I had only fasted for 12 hours and the nurse refused to do it. At the follow up appointment the phlebotomist said of her 'Silly woman'
Is there a right or wrong fasting time ?
Good question, I have only ever been asked to fast for 12hrs for blood tests. I would be interested in a definitive answer, will watch this space 
Now I just lie when I go
When I had one at a major London teaching hospital they said eight hours .
Some GP practices like people to fast, it is mainly for the cholesterol test, AFAIK none of the other tests are affected by the fasting - most web sites state 9 - 12 hours as sufficient. 14 hours is ridiculous
I used to have to fast for 12 hours (which included sleep obviously) but now for my HbA1c and my cholesterol checks I no longer have to fast at all. I believe there is now a new way of testing that doesn't need fasting.
I will ask about that when I next see the doctor.
I've no idea is the honest answer. Perhaps its regional variations. Or a progression of my condition. I'm inclined to go with ceejayblue . I no longer have to fast. I'm not too bothered either way. I never found it difficult, but know several people who struggle to survive without their morning cuppa.
It is not a problem but there should be a definite time.
8-12 hours over here.
We noticed there was a difference in results, which was important especially when the result was at the high end of the range and might have meant the difference between staying the course or retesting to confirm diabetes
Non diabetic but advice pleae
diabetic neuropathy
Type one diabetic 
Diabetic Diet