In a prior post, I quoted the following from the Zohar:
At the time of the End of Days, according to the hour of the day, at the time that the sun shines, from the 6th Day, at the time that is ready according to the count of years, of Yovel and Shmitah together, which is רע"ד (Raa'd, 274 in Gematria) from the 6th Day. At that time a single voice is prepared to awaken at the heights of the upper heavens, a sad and bitter voice, such that hasn't been since the day that the world was created.
The Zohar (Raya Mehemna on Parshat Behar 118:b) says the following about Shmitah and Yovel:
Shmitah is the lower Shechinah, which is from 7 years. Yovel is of Upper Imma, Binah, which is for 50 years, and in it B'nei Yisrael will establish their geneologies when they come out of Galus.