I agree with the above answers, which clearly apply in this context.
Keep in mind that in other contexts, you could have a slightly different meaning:
"In 1999 I spent my first Christmas in my home on Smith Street." = depending on context, this could mean that Christmas of 1999 was my first Christmas ever (I was less than one year old at the time). Or it could also mean that it was the first time that I spent Christmas on Smith Street, either because I just moved to that home or because I was always spending Christmas somewhere else in previous years. The latter meaning makes no reference to age.