Around here we have two majorly expensive months: December (Christmas) and August (Back to school). I would imagine many families can relate. I'm sure that everyone maxes out their monthly budgets at those times of the year.
But I think I've got you beat. My family, in an extraordinary display of inadequate forethought, has also managed to toss birthdays into the morass. My darling Angel was born just days before Christmas, ensuring that forevermore shall her birthday presents be wrapped in Christmas themed paper! Not to mention the difficulty of choosing a time in December, when everyone else is just as busy (and broke), to have a birthday party. And of course the expense of a separate birthday gift over and above any Christmas gifts.
And then there is the Teen. While I had no direct influence on the date of his birth, (I was packing for my first year in college at the time!) I find myself shopping for a birthday gift along with the purchase of an entirely new wardrobe! (Partially due to a growth spurt but mostly due to a general destructiveness when it comes to...well, pretty much everything he touches.) He has more than once had the misfortune of this birthday actually landing on the first day of school, which probably takes the shine off of it a little.
I know what you're saying. If I would shop early, or budget more appropriately, this might not be such an issue. And to that I say, "Pfthtffththptht!" (That's the phonetic spelling of someone giving a 'raspberry'.) I've tried buying birthday gifts ahead of time, and let me tell you that in the land of 9-17 year olds, a week can indicate 4 different mind-changes on what they want for their birthday. Imagine if I had bought the gift two months ago?! Talk about last season/obsolete!
I suppose the only way to make this problem any worse is if we had a birthday during tax season! (Oh, wait...)