hair today gone tomorrow?

one explanation for why Brian's (Tom Cruise's) hair changes lengths threw out the movie is that the movie takes place over aproximately 3 years. After Brian gets in a fight with Doug and quits his job at Cellblock when we see him next in the Bahamas it is 2 years later. Doug even says when they meet in the bar that he hasn't seen him in 2 years. Then when he is in the bar with Jordan with a poem for his unborn child it is almost 9 months after leaving the Bahamas.

This nitpick shouldn't be refuted

Tom Cruise's hair does in fact change drastically in scenes that are supposed to be subsequent. In one particular scene when Tom is looking for Jordan at her apartment Tom's hair is short, in the following scene when he goes to find Jordan at her parent's apartment his hair is long and then when he is in the apartment waiting for Jordan his hair is short. This particular scene is over the course of 1 day probably less than an hour or two, not nine months or a year, his hair is definetly different and therefore a nitpick.