How can I convince a Jehovah's Witness that there is nothing improper about commemorating a birthday?

The Jehovah's Witnesses do not observe birthdays for the following reasons: (1) Birthday has pagan roots. (2) The early believers did not celebrate birthdays. (3) The only commemoration a Christian should keep is Christ's death. (4) And that the Scripture never mentions a servant of God celebrating a birthday. But are these reasoning accurate and logical? 1. If their rationale for not believing and celebrating something is because of its pagan roots, then they should stop commemorating Christ's resurrection because of its pagan origin. Aren't they aware that Osiris, Tammuz, Adonis and Attis, Zagreus, and Dionysus were all said to have resurrected? But we know for certain that these so-called gods and their resurrection are the creations of pagan minds. Jesus' resurrection was historical, observed firsthand by hundreds of people during his lifetime, including his inner circle disciples. 2. It is also not true that the early Christians did not observe birthdays. In fact, many celebrate John the Baptist's birthday. If it is possible to rejoice on the first day of birth, why can't this day be celebrated every year? This has been practiced since the Old Testament days. And you will have joy and gladness, and many will rejoice at his birth, - Luke 1:14 Every year when Job’s sons had birthdays, they invited their brothers and sisters to their homes for a celebration. On these occasions they would eat and drink with great merriment. - Job 1:4 The Living Bible 3. The burden of proof falls on the Jehovah's Witnesses to demonstrate from the Scripture that Christians should only honor Christ's resurrection, not his birthday. 4. The truth is that Scripture says there is nothing wrong with celebrating one's birthday. Just because pagan leaders such as Pharaoh and Herod celebrated their birthdays doesn't mean we shouldn't too. The major issue is not the birthday itself, but rather how we commemorate it. This is why Job had to make sacrifices to ensure that his children's sins were forgiven in case they cursed God in their hearts during the celebration. And when the days of the feast had run their course, Job would send and consecrate them, and he would rise early in the morning and offer burnt offerings according to the number of them all. For Job said, “It may be that my children have sinned, and cursed God in their hearts.” Thus Job did continually. - Job 1:5 Sadly, Pharoah and Herod celebrated their birthdays in an ungodly manner. Isn't there anything to celebrate if we are constantly reminded of our birthday? A day when the Lord let us see the light of morning and take our first breath of air? The Jehovah’s Witnesses are simply being legalistic.