How long did john the babtist ministry last?

1260 days :)

Explanation:

Secular historians date that around 29 A.D. John mentions four Passover feasts (John 2:23; John 5:1; John 6:4; John 13:1). The Lord’s ministry began before the first and He was crucified on the fourth Passover. That suggests His public ministry was slightly more than three years. If we accept that the Lord’s crucifixion was in 33 A.D., His public ministry began in the latter part of 29 A.D. when He "began to be about thirty years of age" (Luke 3:23), perhaps as much as 6 months after John began to preach. Matthew places the death of John the Baptist before the feeding of the 5000 (Matthew 14:1-13, 21). John tells us the feeding of the 5000 took place shortly before the third Passover(John 6:4-13), about two and a half years into the Lord’s ministry. John had been in prison for a time before that, so his ministry - before imprisonment - may have been as short as two and a half years. Such a valuable man! Yet he fulfilled his course (Acts 13:25) within three years. Apparently, the Lord gave neither John nor his disciples an explanation of the divine plan, for "His ways are past finding out" (Romans 11:33).