All sabbaths, the weekly rests, the special rests, are teaching models for the resurrection and afterward.
Each one teaches a different aspect. Like passover illustrating an end of slavery.
All sabbaths are "lasts"
So how I keep that, what I embrace about it, is supposed to be set apart. It is supposed to be a different kind of thing to look forward to than every day leading up to it.
These are who will rest on it -
God
Me
family
manservant, maidservant, ox, ass, cattle, stranger within gates
Salvation causes me to keep it properly, and that keeping does not have to be physical, though it helps in understanding.
Today, I hauled building materials for my mom and aunt, but put off actually building anything for later. I cleaned my kitchen. I purposely overslept. I didn't worry about a bill that is due today. I still kept the sabbath, even though by God's calendar, the next four sabbaths are on tuesday, tuesday, tuesday and wednesday.
Proper understanding of it did not save me, but was a part of defining salvation.