Many ask: "What does it matter how long Yeshua's ministry lasted?" The reason this matters is because there are numerous prophetic parallels between Yeshua's first coming (as the Suffering Servant) with His future coming as the Anointed Son of David, King of Israel. There are at least 3 levels to Daniel's 70 Week Prophecy and Yeshua's ministry chronologically falls into precisely that, 70 Weeks.
The following quotes taken from The Greatest Story NEVER Told! The Jonah Code and the Seventy Weeks Prophecy of Daniel by Michael Rood.
"From when Yahshua was baptized in water, into the Spring, the Summer, and all the way around to the Fall, showing you week by week exactly where Yahshua was with no lapse in time at all. Then we find out there is a miracle that takes place in every one of the Gospels, the miracle of the feeding of the five thousand. It takes place two weeks and three days before the Feast of Tabernacles (in everyone of the Gospels). However, in some of the ancient Greek texts, 8 Greek words were added in: "and Passover, Feast of the Jews was nigh". And what that did was artificially expand the length of Yeshua's ministry. They added, literally, 6 and a half months of absolutely blank canvas into the Gospel record."
There are many places in our English Bible translations where Yeshua is falsely depicted as being anti-Torah (no doubt He was anti-Takkanot), but it is rare that entire sentences are added into the text like in the case of John 6:4 for such purposes. Rood continues:
"Then we see what they [scribes] did add was a Passover that doesn't exist. A Passover that Yahshua never goes up to. We see exactly what He is doing for the next two weeks. He never goes any where near Jerusalem, but He does feed five thousand people with leavened bread (which I now affectionately refer to as the Feast of Leavened Bread). Five days later, He feeds another four thousand people with Leavened Bread. He teaches a whole synagogue full of people who are disobedient to the Torah and they're hanging out in the Galilee instead of being up at Jerusalem. For this whole two week period of time, He is doing nothing but violating the Torah, if those words were in the original text."
Rood then describes how this falsified Passover is followed up with five and half months of more blank canvas until we come all the way back around to the Festival of Tabernacles (Sukkot).
"...Yahshua's ministry, if it is a fulfillment of Daniel's Prophecy, is going to be 70 weeks, exactly 490 days from the day He is baptized until the day He baptizes with the Holy Spirit, one of the layers of Daniel."
"The early church fathers, the first and second centuries after the Gospels were written, Clement of Alexandria, being the foremost on this, said that Yahshua's ministry was about one year in duration. Four other church fathers in the first two centuries afterwards said that His ministry was about a year in duration. And you know what all the rest of the church fathers said? Absolutely nothing. They didn't dispute it!"
Quotes taken from The Greatest Story NEVER Told! The Jonah Code and the Seventy Weeks Prophecy of Daniel by Michael Rood.
The other year which is typically used to artificially expand Yeshua's ministry is determined by reckoning John 5:1 with yet another Passover, when it is actually the Festival of Shavout (Pentecost). Adding these two extra Passovers into the Ministry equation is the reason modern teachers insist Yeshua ministered for 3 and a half years before His ascension back to the Father. When you take these two non-Passovers out of the equation, His ministry beautifully shrinks back down to 70 Weeks (490 days). To go into this in greater detail, get Rood's teaching: 70 Week Ministry of the Messiah.