Blv lasts 3 hours max on me, and that is 4-5 sprays of it also. Most people I've talked to get about the same longevity from it also.
Personally I've always used it as a evening scent so 3 hours works just fine. But if you were wanting it to last all day, do a search for different longevity increasing threads here in this forum. I'm not going to go in depth but they are very useful for stretching another hour out of your frag's.