I don't know, but I'm willing to bet Elsa is a winter baby and Anna is a summer baby.

Maybe Elsa was born on the night of the Winter Solstice (December in the Northern Hemisphere) during the Aurora Borealis and was somehow touched by the magic of their lights, and that's how she got their powers. I'll bet Anna was born in spring or summer.

I think Elsa for December and Anna for January or June. :)

I like your theory, Tygers_Eye. c:

^

When you think about it, Frozen Heart just foreshadows every bit of the movie. "Watch your step! Let it go! Ice has a magic can't be controlled! Stronger than one! Stronger than ten! Stronger than a hundred men!" and "This icy hold both foul and fair has a frozen heart worth mining. Cut through the heart. Cold and clear. Strike for love and strike for fear!"

ANYWAY, the ice harvesters also say "Born of cold and winter air and mountain rain combining." I imagine some sort of winter magic or aligning of cold elements gave Elsa her powers. What's more magical than the longest night of winter coupled with the Aurora Borealis?

I agree with Tygers_Eye on Elsa's birthday, and I think Anna was probably born in spring. Spring Equinox, perhaps?

I agree with Tygers_Eye. I think Anna was born in May and Elsa was born in December.