Since the Foundation of the World, God planned on this day to bring fallen mankind back from the consequences of our self-inflicted wounds and rebellious separation from Him.
In the church cycle, it is the darkest day of the year. But it is meaningless, unless each of us---individually---grasps he or she is a sinner in desperate need a Savior. Even if outward appearances look as if we're doing just fine, we are still separated sinners in need of a Savior, from our hearts outward.
Once we grasp this, we are in a position to find and accept the Savior of the World in Christ Jesus, and begin our own personal relationship and journey with Him.
Right there on the Cross, HE IS. And today is suffering and dying for each one of us.
It is a day for sober, quiet reflection and whatever comes from that.
When Easter falls each year, and how it is calculated.