There are several differing systems falling within just a few years or months of each other. According to my calculations, Mar/Apr 2009 (Nisan/Aviv) through Mar/Apr 2010 (Nisan/Aviv) will be the next Sabbath/Shmita year and Mar/Apr 2045 through Mar/Apr 2046 will be the next Jubilee (Yovel/Yobel).
- Next Shmita: 2009/2010 (Aviv reckoning)
- Next Yobel: 2045/2046 (Aviv reckoning)
According to this interpretation, we are currently in the 7th year of a 7 year Shmita cycle. For more details and a longer explanation, see How do we know the Shmittah (Sabbath) and Yovel (Jubilee) Year Cycle? and Table of Sabbath and Jubilee Years.