According to the Gospel of Matthew (2:1-16), the wise men or Magi followed a star to the birth place of Christ. It was written that they were from the east and that they brought three gifts to Christ; gold, frankincense and myrrh. Since there were three gifts its has been concluded that there were three Magi. It is not known if the Magi became Saints or are considered Saints, all that is known is that they brought gifts to Christ the night he was born.
The names for the Magi are given in extra-Biblical tradition as Gaspar, Melchior and Balthasar. The feast day of the Magi is December 25.
There are numerous variations of the names of the Magi in Greek but the most common variation is for the name Gaspar which in Greek is Ιάσπερος (yiasperos) which translates into english as Jasper.
Therefore the name day for anyone with the name Jasper, Gaspar, Melchior or Balthasar is December 25