Rectified Hebrew calendar
The Rectified Hebrew calendar is a proposal for calendar reform by Dr. Irv Bromberg. It is a lunisolar calendar intended to replace the Hebrew Calendar. The months are the same length but the main difference is that it adds a leap month 130 times every 353 years so that 4366 months equal 353 years. It adopts a variable length for the molad, the length of a mean lunation. It is a leap year if the remainder of (Year * 130 + 268)/353 is less than 130. Each month now has 29.53087191358024691358 days and each year has 365.242333364 days - perfect for the next 8 millenia!