Sorry to say, but this sentence doesn't make much sense. Are you trying to say, "life is today, enjoy it"?

life is only two days? that's not very long.

Since this is a Spanish saying, and it looks like you're trying to translate it as literal as possible, then it would be: Life is two days, enjoy them! You use "is" instead of "are" because "life" is singular. Personally, I would add the word "only": Life is only two days, enjoy them!