This is what you do:
Every year's calendar should be only 11 months long. We can make up the missing days by extending weekends on the remaining months. Each year a different month is omitted. Eg. the the year this is implemented we don't have January. Next year no February, but January is back, the 3rd year no March, etc.
This can have many benefits:
-Longer weeks means an extra day off for most people. For people that have to work, more opportunity for overtime pay. People on salary will see their average pay per check rise, as there are less months to be paid.
-Every 12 years you have one less birthday, so you don't age quite as fast.
-Every 12 years there is no tax day. Yay! no taxes for that year.
-No Christmas on the 12th year--mixed feelings about this, but Christmas is over hyped anyway.
-COBOL programmers will have more to do :)
Of course this could be confusing for many, but most people seem a bit confused anyway, myself included a lot of days, so this shouldn't be much worse than normal. And the astrologers won't be happy.