Even when it's not.
I honesty can't think of one person I know who doesn't bitch, moan, or complain about something, at some time.
Does that mean we aren't grateful? Of course not.
We're human and thus, we vent.
Today, if you feel the need to whine, go for it.
I know when I get cranky, at least these days, I can usually reign it in. That's the beauty of practicing yoga and gratitude and meditating and journaling and blah-blah-blah. (Same song, different day.)
Life IS beautiful. YOU are beautiful.
Go now, and make beautiful things happen!