So from 1.0, to 1.6.0, to 1.8.0, date got slower. Since then, date has gotten a little faster. For example, in ruby 1.8.7, instantiating date objects is about 46% faster than in 1.8.0. However, it's still half the speed of 1.6.0 and a third of the speed of 1.0.
In 1.9.2, the code looks and performs pretty much the same as it did in 1.8.7.
By that I mean, while ruby 1.9 is much faster than 1.8, if you take the 1.9.2 date code and run it on 1.8.7, it's about the same speed as the 1.8.7 date code.