Birthday rule: (noun) A rule which states that one must celebrate their birthday for a total of one month. The celebration starts two weeks before the actual birthdate and continues two weeks past the birth date, counting out exactly 30 days of celebratory time. My Birthday rule goes into effect today and I have put together a wish list, prompted by an episode of Sex and the City. If people can register for Weddings and Baby showers, why not for birthdays? My latest obsession of leather and sequins are abundant!