October 14, 29 A.D., the date of Christ's baptism
Fact: Other approach to determining the date of Jesus’ birth is from information about John the Baptist. Elizabeth, John’s mother, was a cousin of Mary and the wife of a priest named Zacharias, who was the “course” of Abijah. 
(Priests were divided into 24 courses and each course officiated in the Temple for one week, from Sabbath to Sabbath.)
When the Temple was destroyed by Titus on August 5, 70 A.D., a witches cross-quarter Sabbath, the first course of priests had just taken office. 
Since the course of Abijah was the 8th course, we can track backwards and determine that Zacharias ended his duties on July 13, 3 B.C. If the birth of John took place 280 days later, it would have been on April 19-20, 2 B.C., precisely on Passover of that year. The birth of John and the birth of Jesus was separated by 5 months. Therefore, we have again the autumn of 2 B.C. as Jesus’ probable birth date.
Fact: John began his ministry in the 15th year of Tiberius Caesar.  The minimum age for the ministry was 30.  As Augustus died on August 19, 14 A.D., that was the accession year for Tiberius. If John was born on April 19-20, 2 B.C., his 30th birthday would have been April 19-20, 29 A.D., or the 15th year of Tiberius. This seems to confirm the 2 B.C. date and, since John was 5 months older, this also confirms the autumn birth date for Jesus.
John’s repeated introduction of Jesus as “The Lamb of God”  is interesting as John was indeed born on Passover, himself sacrificed for the new covenant, making a first in two ways-the last old testament prophet to be slaughtered by those he came to serve and the first New Testament cross bearer to pre-echo the Great Lamb of God he came to represent.