In addition to the biblical Sabbath day, Jesus observed the biblical festivals recorded in the Old Testament; the Gospels do not show Him ever being accused of violating the Holy Day observances. John 7 records Him teaching at the temple during the Feast of Tabernacles. All four Gospels record His actions leading up to and during His last Passover with His disciples the night before He was crucified.
The Church that He founded was started on the Feast of Pentecost (Acts 2:1-4 Acts 2:1-4  And when the day of Pentecost was fully come, they were all with one accord in one place.
 And suddenly there came a sound from heaven as of a rushing mighty wind, and it filled all the house where they were sitting.
 And there appeared to them cloven tongues like as of fire, and it sat on each of them.
 And they were all filled with the Holy Ghost, and began to speak with other tongues, as the Spirit gave them utterance.
American King James Version×). After His death and resurrection the apostles continued to keep these biblical feasts (Acts 18:21 Acts 18:21But bade them farewell, saying, I must by all means keep this feast that comes in Jerusalem: but I will return again to you, if God will. And he sailed from Ephesus.
American King James Version×; Acts 20:6 Acts 20:6And we sailed away from Philippi after the days of unleavened bread, and came to them to Troas in five days; where we stayed seven days.
American King James Version×; 1 Corinthians 5:6-8 1 Corinthians 5:6-8  Your glorying is not good. Know you not that a little leaven leavens the whole lump?  Purge out therefore the old leaven, that you may be a new lump, as you are unleavened. For even Christ our passover is sacrificed for us:  Therefore let us keep the feast, not with old leaven, neither with the leaven of malice and wickedness; but with the unleavened bread of sincerity and truth.
American King James Version×; 1 Corinthians 16:8 1 Corinthians 16:8But I will tarry at Ephesus until Pentecost.
American King James Version×).
Since Jesus, the apostles and the early Church observed these biblical festivals, why don't churches today keep them and teach about them? Instead they have substituted other holidays for the Holy Days of the Bible.
If Jesus had wanted His Church to observe festivals different from those that He observed, shouldn't He have left this instruction? He was clear and emphatic in His instructions to His disciples. It's hard to imagine that Jesus would have set an example of observing the biblical Sabbath and festivals but later led or inspired His Church to dismiss them and replace them with alternate observances that originated in paganism.
Christmas and Easter are nowhere taught in the Bible, yet they have become the greatest holidays of popular Christianity. Likewise Sunday became the major day of worship instead of the seventh-day Sabbath. But why? And how? If you'd like to learn more about the true biblical festivals and how they were replaced with holidays that had nothing to do with Christianity or the Bible, request or download the free booklets Holidays or Holy Days: Does It Matter Which Days We Observe? and God's Holy Day Plan: The Promise of Hope for All Mankind.