Everyday is cause for celebration. Even if you are in the midst of a struggle. It doesn't matter if change and challenge have overwhelmed you, it's cause for a celebration!
You don't need the seas to remain calm to appreciate goodness. The absence of adversity is not a condition of happiness.
Celebrate because you are breathing. Rejoice in being alive. Paint the town red with your smile. Have a party in your heart.
Your purpose is not to revel in misery, but to find merriment in the mundane, to seek joy in the midst of sorrow, and to simply have a ball! You don't need an invitation to celebrate...today is a momentous occasion, simply because you are here, celebrate that.