Dear Amelia, like you I, and many others read that to be a record of birthday celebrations, and more tellingly, set in the part of the Job story that shows Yaweh's approval of the man and what he is doing, and showing the family of Job going about there normal life before that rat satan got involved.
The WT's wriggling, disingenuous explanation for why these are not birthday celebrations and ones approved by Jehovah at that, is to say the least pathetic.
Don't bother to look it up. you will be sick.
This whole thing goes back to Rutherford's wish that JW's be different, it really didn't matter if scripture really backed the difference, it was there as a marketing tool, the one true religion had to have things that marked it as different from the other 2000 plus sects of Christendom.
Hence countless children have missed out, including my own, on a normal happy childhood.
I weep (right now actually, as I write) for what I did not give my kids, may any active Witness reading this not make the same mistake, your children's early years are gone in a flash, you cannot get them back.