Yes, the WT printed an article (questions from readers) many years ago discussing Job's children's non-celebration of birthdays. They updated that again in the last 10 years - which was basically a summarized reprint of the original article. I don't have my cd on me so I can't print the references. Sorry.
Basically, the WTS says that the Hebrew language has two words: one for Day and one for Birthday.
This is true. However, what the WTS doesn't tell you is that further in the book of Job the same word (for day) is used to mean 'day of birth'. So at best there is no conclusive evidence either way. Did the kids celebrate their birthdays? Did they celebrate the harvest?
The way I see it, the book of job either talks about birthday celebrations or thanksgiving. I win either way.
There are much more detailed threads on this subject.