Since the early centuries AD until the recent times there have been contradictory theories about the length and duration of Jesus Christ's public ministry. The ideas vary from 3 years (today perhaps the most common opinion) to 1 years or even 4 years. In connection with this mention is made of the actual years when Jesus was to have ministered.
The following chart explains from the chronolgical references in Luke 3 and John 2 the time and duration of Jesus' public ministry, which can be calculated to have been about 1 year (from shortly before the Passover in 27 AD until the Passover in 28 AD. This is also confirmed by the records in the gospel of John about Jesus' visits in Jerusalem for the annual feasts.