Most Catholics go to the Vigil Mass (4 PM) to get it over with. But liturgically, Christmas has three distinct Masses, each with different readings.
1. Mass at Midnight (Angels)
Historically celebrated in the dark. The Gospel is Luke 2 (the decree of Caesar Augustus). Symbolism: The Light shining in the darkness. The birth of Christ in the silence of the night.
2. Mass at Dawn (Shepherds)
Celebrating as the sun rises. The Gospel is Luke 2 (the shepherds visiting the manger). Symbolism: The Light spreading to the humble.
3. Mass during the Day (King)
The solemn high Mass. The Gospel is John 1 (In the beginning was the Word). Symbolism: The Eternal generation of the Son from the Father. The theology of the Incarnation.
Why Midnight?
Because Wisdom 18:14 says: "While gentle silence enveloped all things, and night in its swift course was now half gone, your all-powerful word leaped from heaven."
Stay up late. It's worth it. MyPrayerTower app.