And it was at Jerusalem the feast of the dedication, and it was winter. And Jesus walked in the temple in Solomon’s porch. Then came the Jews round about him, and said unto him… (John 10:22-24a)
Did Jesus religiously observe the Feast of Dedication as an ecclesiastical holy day even though it was not instituted by God? If so, does it therefore follow that ecclesiastical holy days may be instituted by men and observed without good and necessary consequence from Scripture?
1. Time and place of the narrative.
The fact that John 10:22 merely mentions the feast for the setting of time and place and to explain why there were crowds Jesus could preach to (v. 24 ff.), is enough to remove this as a proof text for man-made holy days being lawful. Many commentators note that this is merely the setting without using it as an argument for whatever their position is on holy days. This shows that this text can be, and most often is, exegeted neutrally outside of a polemical context.
Further, the context implies that the reason Christ was there was to preach to the crowds, not necessarily to celebrate the feast. As John Calvin commented, “Christ appeared in the temple at that time, according to custom, that his preaching might yield more abundant fruit amidst a large assembly of men.”  Lutheran commentator J.A. Bengel similarly noted, “He did not go up to Jerusalem purposely, for the sake of this ecclesiastical feast (as He had done on account of the other feasts, established by the Law), but He was present at it owing to circumstances.”  Leveraging Franciscus Junius and Rudolf Hospinian, George Gillespie observed, “Christ’s being present at it proves not His approving of it. ‘Christ did not honor the feast day specifically,’ says Junius, ‘but the assembly of the righteous gathering on a feast day; for all opportunities of that kind for sowing his Gospel Christ pays attention to and seizes. ‘As if indeed’ (says Hospinian) ‘Christ left for Jerusalem for the sake of the Feast of Dedication.’ Nay, but He saw He had a convenient occasion ‘to teach a multitude of men who had come together for that feast day.’”  John Collinges (1623-1690) states that it would be just as unwarranted to argue for a seventh day sabbath from the fact that Paul preached the gospel to the Jews on that day as it would be to argue for man-made ecclesiastical holy days from the fact that Jesus was teaching in Jerusalem during the Feast of Dedication. 
While it is reasonable that this point definitively answers the question, for those who are still unsure, there are more factors to consider which make this argument for holy days even more spurious:
2. Identifying “the feast of the dedication” (ἐγκαίνια).
What exact feast is being referenced in this text? It is probably in reference to Hanukkah, but not all commentators agree. Poole discusses the various possibilities. Bullinger leaves it doubtful. Maldonatus says that the fewest authors think it refers to Hanukkah.  William Ames wrote, “Now what Feast of Dedication this was and whether it were merely of human institution; this hath always been, and is still in great question. Nonnius taketh it for that which Solomon appointed: Chrysostom, Theophilact, Euthymius, Cajetan, Calvin, etc. interpret it of that which began in the time of Ezra: Others of that instituted by the Maccabees (1. Mac. 4).” 
The use of this verse on the question of man-made holy days depends on the answer to this question. Scriptural warrant for instituting and observing ecclesiastical holy days would require stronger proof than can be gathered from this passage. However, even if we can have a high degree of certainty about which feast this is, we must still ask a more germane question:
3. The character of this feast at the time.
What was the character of this feast at the time of this narrative in John 10:22? There is even more genuine disagreement and historical uncertainty here. Josephus, summarizing 1 Maccabees 4:52-60, describes how Judas Maccabeus initially celebrated Hanukkah and rebuilt the infrastructure. Alfred Edersheim describes some of the traditions later observed by different schools of thought over time and what the Talmud records concerning various traditions and ceremonies.  Clearly the Talmud contains many extra and late Pharisaic traditions regarding this feast. But did the Lord participate in any or some of these things? Scripture itself does not answer this question, and it certainly does not describe Jesus religiously observing any Pharisaical innovations. The character and rituals of the feast may have drastically changed over time. It is uncertain what exactly the feast was like in Christ’s day. Scripture alone is our rule of faith and practice and its silence about this confines what we can know about it and what we can base our exegesis, application, and practice on.
Ecclesiastical or Civil?
George Gillespie does not classify this feast as a civil celebration, but he distinguishes between civil days of celebration and ecclesiastical holy days. “It appears, that the days of Purim were only appointed to be days of civil mirth and gladness, such as are in use with us, when we set out bonfires, and other tokens of civil joy for some memorable benefit which the Kingdom or Commonwealth hath received. For they are not called the holy days of Purim, but simply the days of Purim, a day of feasting and of sending portions one to another (Esther 9:19-22), no word of any worship of God on those days.”  Many theologians make the same distinction and do not contend that the Feast of Dedication was an ecclesiastical holy day at all. Daniel Cawdrey argues extensively against an opponent that it was a civil day similar to the Fifth of November rather than a holy day.  Matthew Poole and Matthew Henry compare Hanukkah to Purim and say that it was not an ecclesiastical holy day, but rather a civil day of thanksgiving for the restoration of their freedoms. In this regard it would have been a similar holiday to an Independence Day from the Greeks. Poole writes:
“Magistrates certainly have a power to appoint public days, yea, annual days of thanksgivings, for mercies never to be forgotten. Indeed they cannot make a day holy, so as it shall be a sin against God to labour in it, or to use any pleasures (as in the case of the sabbath); but they may command the public worship of God to be performed on particular days, and men ought to attend it when with convenience they can; only they ought to take care that such days be not spent in luxury and profaneness, and that they be for signal providences, and not so multiplied, and frequently renewing, as that the service of them degenerate into mere matter of form. Whether Christ went up in order to the feast, or because of the great concourse of people he knew would be there at that time, cannot be determined.” 
For the purposes of this post it is immaterial whether this feast in Jesus’ day was an ecclesiastical holy day or a civil day of celebration because there is nothing in John 10 that indicates his observance of the day. But it is a useful exercise to establish that there are multiple possible inferences and that there is not enough information in Scripture itself to draw good and necessary consequence from for biblical warrant for the institution and religious observance of man-made ecclesiastical holy days today.
4. Why didn’t Jesus reprove the feast?
One may insist that man-made holy days are lawful because John 10 does not record Jesus reproving the feast. This, however, is a very tenuous argument and it does not follow from good and necessary consequence.
A.) It assumes specific rituals and a character about the feast that not all would agree with (see point 3 above).
B.) It would prove too much. There are some positions on this topic which approve of observing holy days in alleged Christian liberty but which would not approve the extent to which ecclesiastical traditions were pressed upon the conscience by the Pharisees. So if Jesus did not reprove the feast itself in John 10, he also did not reprove the Pharisaical urging of it upon people’s consciences. So there is no middle ground with this argument. To be consistent one must go all the way to the Papist view of holy days where they are necessarily pressed upon the conscience—which would be absurd and obviously wrong.
C.) Plenty of other scriptures prove that man-made holy days are unlawful. This statement is not even in dispute in the Reformed camp at all. Those in the broader Reformed camp who observe Christmas, Easter, etc. assert that they do it out of “liberty” and not because one day is holier than another (e.g. 2nd Helvetic Confession). I believe they are wrong about that (cf. 8 Reasons Christian Holidays Should Not Be Observed), but most in the Reformed camp do not dispute the principle that men or traditions cannot make days holy. Laudian, Tractarian, and Lutheran positions notwithstanding.
D.) Lastly, there are many other occasions where Jesus did not reprove every relevant sin that he could have. Because he rather focused on more urgent matters and calculated his interactions with people for specific purposes. See for example his interaction with the rich young ruler (Mat. 19:16-22), and how he only lists the second table of the law. Does this mean that the man had not broken the first table, or that the first table is not important? No. That is naïve exegesis.
Hence, even if the feast mentioned in this text were an unlawful ecclesiastical holy day, Jesus not reproving people for observing it is immaterial to the practical question of whether the church can ordain and observe such types of holy days today.
To conclude, John 10:22 merely mentions the feast for the setting of time and place and to explain why there were crowds Jesus could preach to (v. 24 ff.). The text gives no indication that Christ was religiously observing the feast. The standard of proof for such an interpretation is much higher than can be supported by such a passing statement in v. 22. There are several critical details that must be established for this text to serve as a proof for instituting and observing ecclesiastical holy days: 1. That the Feast of Dedication in the time of the narrative of John 10 was an ecclesiastical holy day not instituted by God. 2. That there were man-made rituals or superstitious abuses of divine ceremonies promiscuously engaged in at that time. 3. That Jesus treated the feast no different than divinely ordained feasts and religiously observed it as such. From what we’ve examined here, it is not tenable to prove all three of these elements.
 John Calvin, commentary on John 10:22.
 J.A. Bengel, Exegetical Annotations on the New Testament, John 10:22.
 George Gillespie, Dispute Against the English Popish Ceremonies III.vi.11, p. 250; citing Franciscus Junius, Opera Theologica (1607) 2.857, and Rudolf Hospinian, De Orig. Templ. 4.2.
 John Collinges, A Modest Plea for the Lord’s Day, p. 45.
 Gillespie, ibid., citing Heinrich Bullinger, In Divinum Jesu Christi Domini, book 5, p. 123, and Johannes Maldonatus, Comentarii in Quatuor Evangelistas, vol. 5, p. 255.
 William Ames, A Fresh Suit Against Human Ceremonies in God’s Worship, p. 318.
 Josephus, Antiquities of the Jews 12.7.7; Alfred Edersheim, The Life and Times of Jesus the Messiah, pp. 631-635.
 Gillespie, ibid., III.vi.8, p. 245.
 Daniel Cawdrey, The Account Audited and Discounted, Exercitation 3. Of Christmas and other Festivals, pp. 416-418.
 Matthew Poole, commentary on John 10:22.