Phat writes:
What good is "holiness" without someone or something to attribute the "holy" to?
"Remember the Sabbath, to keep it holy" = "Don't work on the Sabbath"
The Sabbath is "holy" because even God can't work 24-7. In that sense, we're putting God into the Sabbath. But it's also common sense.
Similarly, the Winter Solstice is a sign that the sun will come back, life will go on. It reminds us to look at the long term instead of focusing on short-term woes. If that isn't "attribution" enough for you, feel free to spackle on a coat of "Christ".