How are the years counted?

Joshua started to count the years for the jubilee 14 years after crossing the Jordan River. They counted 17 jubilees until the captivity in Babylon. The first temple lasted 410 years and was destroyed by the Babylonians in the year 586 B.C.E., a year after a sabbatical year.

When Ezra came to Jerusalem seven years after the building of the second temple, they started a new counting. The second temple lasted 420 years and was destroyed by Rome in the year 70 C.E.

When the Rabbis started to count the years in the land after the first aliyah in the year 1881-1882 they proclaimed the year 1888-1889 (5649) as a sabbatical year. The most recent sabbatical year was 2007-2008 (5768)

During that year there were news reports about how the Eternal protected those who kept the rules of the year of shmitah in Israel. Bananas and potatoes were ruined by frosts except the fields in which the sabbatical year dictated by rabbinical counting was respected. In this link you can read about this and see photographs about this miracle: