The fourth of the 10 commandments is remember my Sabbath day to keep it holy. There is a lot packed in to this.
Remember: We who are true sons, Humankind created by voice manifest through the Word of Creator G-D, the one in the sixth day of the first creation are admonished to remember. Remember how it was before the rebellion of Lucifer, the fall, and the destruction of the first creation. Remember how it is to be completely whole in The One.
My Sabbath: Creator G-D the ONE worked on creation for 6 specific segments of focus and energy. We in time space have called them days. They are not days like our Sun supplies us with 24 hours as we spin on earths axis. Those first 6 segments in the first creation are defined by the activities and the focus of Creator G-D in each of them. When Creator G-D saw that the activities of creation were finished and it was good, rest was introduced.
The Sabbath as first celebrated by Creator G-D is on Saturday in our current calendars. When we obey the command to Sabbath is critically important. If we get it wrong we are falling in to line with the rebellion and worshipping the gods.
We have free will to run our lives as we see fit. So we can attend any meetings or services we want any day of the week.
Sabbath is Saturday.