Well, a nobleman in both senses of the word, like Ambrose, deserves as such, in my opinion.

In Catholic lands, it is the feast day of a particular saint which corresponds with the day a child is baptized. Usually the day after his or her birth, but it may take a few more days, up to a week. I was baptized the day after I was born, so I suppose my saint's day is the Feast of Sabas Stratelates.

I understand he is not Catholic, as many Travelers are not, so my take on this may be rather... skewed.