They need rest in Jesus too. And the church needs to be flexible enough to provide plenty of opportunities for their rest too. Saturday night is good for those who can't make it on Sunday morning. Wednesday night is fine even when it isn't Advent or Lent. We already do that.
Any day is OK, as long as two or three show up.
The heart of Sabbath not a day but the Word. The Word makes any day a holy day. With Jesus, it's no longer the Sabbath day, but simply sabbath. Sabbath happens wherever the Word and the Sacrament are, whenever baptized believers in Jesus are gathered to rest in His Word and recline at His table. We should fear and love God so that we do not despise preaching and His Word, but hold it sacred, gladly hear and learn it.