Birthday celebrations may seem innocent, but are presented unfavorably in the Bible. The two birthdays mentioned were both celebrated by pagan rulers and both resulted in executions of prisoners. Other Bible principles apply to celebrating one's birth, IMO. (Ecclesiastes 7:1) One book on birthdays says the following:
"The Greeks believed that everyone had a protective spirit or daemon who attended his birth and watched over him in life. This spirit had a mystic relation with the god on whose birthday the individual was born. The Romans also subscribed to this idea. . . . This notion was carried down in human belief and is reflected in the guardian angel, the fairy godmother and the patron saint. . . . The custom of lighted candles on the cakes started with the Greeks. . . . Honey cakes round as the moon and lit with tapers were placed on the temple altars of [Artemis]. . . . Birthday candles, in folk belief, are endowed with special magic for granting wishes. . . . Lighted tapers and sacrificial fires have had a special mystic significance ever since man first set up altars to his gods. The birthday candles are thus an honor and tribute to the birthday child and bring good fortune. . . . Birthday greetings and wishes for happiness are an intrinsic part of this holiday. . . . Originally the idea was rooted in magic. . . . Birthday greetings have power for good or ill because one is closer to the spirit world on this day.”—The Lore of Birthdays (New York, 1952), Ralph and Adelin Linton, pp. 8, 18-20." (Quote from RS p. 70)