Per the Rambam, the year 3339, the year that the 1st Beit HaMikdash was destroyed, was the 36th year of the Yovel cycle.
בעשרים וחמש שנה לגלותנו בראש השנה בעשור לחדש, בארבע עשרה שנה אחר אשר הכתה העיר, בעצם היום הזה, היתה עלי יד ה' ויבא אתי שמה
In the 25th year of our exile, on Rosh Hashanah, on the 10th of the month, in the 14th year after the city was hit, in the middle of this day, the Hand of Hashem was upon me and brought me there.
Therefore putting 2 and 2 together, we have that this was 14 years after the 36th year of the Yovel cycle, which would be the Yovel year itself, which starts on Yom Kippur, the 10th of the month, as written here. That would be the year 3353.
This of course follows the counting method of counting of Rabbanan, for according to Rebbi Yehudah, the 1st Beit HaMikdash was not destroyed in the 36th year of the Yovel cycle, but rather the 3rd year of the Yovel cycle.
What I find fascinating about this is that it is written that Hashem gave a special significance to the Yovel during Galut Bavel, as if to indicate that the Yovel cycle itself continued.
Chapter 40 is of course the vision of the future Geulah, the vision of the final Beit HaMikdash, which is related to the next Yovel.