To do it anytime is good. To do it often is great. To do it every day (to paraphrase Julia Cameron) is transformative.
What are you looking for?
I have gotten well, gotten happy, gotten love, gotten clarity. Writing is the reason, or one of the big ones.
Stop reading this right now. Go pick up a pen or a pencil or your keyboard and write about how reading this makes you feel, or about how it doesn't make you feel, or about anything you damn well feel like.
And prepare for your life to change.