@FundieFarmer, I'm copy-pasting (and bolding parts) of the relevant questions and answers from the Westminster Larger Catechism so you can see where the craziness is coming from: Q. 116. What is required in the fourth commandment? A. The fourth commandment requireth of all men the sanctifying or keeping holy to God such set times as he hath appointed in his Word, expressly one whole day in seven; which was the seventh from the beginning of the world to the resurrection of Christ, and the first day of the week ever since, and so to continue to the end of the world; which is the Christian sabbath,[622] and in the New Testament called The Lord’s day.[623] Q. 117. How is the sabbath or the Lord’s day to be sanctified? A. The sabbath or Lord’s day is to be sanctified by an holy resting all the day,[624] not only from such works as are at all times sinful, but even from such worldly employments and recreations as are on other days lawful;[625] and making it our delight to spend the whole time (except so much of it as is to be taken up in works of necessity and mercy[626]) in the public and private exercises of God’s worship:[627] and, to that end, we are to prepare our hearts, and with such foresight, diligence, and moderation, to dispose and seasonably dispatch our worldly business, that we may be the more free and fit for the duties of that day.[628] Q. 118. Why is the charge of keeping the sabbath more specially directed to governors of families, and other superiors? A. The charge of keeping the sabbath is more specially directed to governors of families, and other superiors, because they are bound not only to keep it themselves, but to see that it be observed by all those that are under their charge; and because they are prone ofttimes to hinder them by employments of their own.[629] Q. 119. What are the sins forbidden in the fourth commandment? A. The sins forbidden in the fourth commandment are, all omissions of the duties required,[630] all careless, negligent, and unprofitable performing of them, and being weary of them;[631] all profaning the day by idleness, and doing that which is in itself sinful;[632] and by all needless works, words, and thoughts, about our worldly employments and recreations.[633]

Thanks for commenting! The OPC congregants that I knew were far more lax on the Sabbath than most of those I knew in the RPCNA.  The RPCNA is most definitely its "own thing" even among Reformed Presbyterians. It's not an offshoot of some other branch of American Presbyterianism; it's existed in the U.S. since the early 1700s. They call themselves "Covenanters" after the Solemn League and Covenant of 1643 in which they claimed Christ's lordship over the nations. Thus, they have a strong history of political dissent/refusal to participate in politics in any country which does not explicitly claim Christ's headship. It makes them a bit...unique. All the OPC members that I met were much more into politics! Under the Bible, the RPCNA also adheres strictly to the Westminster Confession of Faith, the Larger and Shorter Catechisms, and the regulative principle of worship, which leads to exclusive acapella psalmody, closed communion, and a very traditional-style worship service.  And yes, the Sabbath-keeping is totally Biblically incorrect. I don't consider myself a Christian anymore, but I still find the history and theology quite fascinating, sometimes in a horrified kind of way. My family would have definitely considered OPC to be theologically sound but incorrect in their worship style; PCA to be "liberal," and PCUSA to be probably apostate! There was some debate as to whether the Pope was the Antichrist; opinions were mixed on that one. If you don't mind, what aspects of faith or worship do you consider to be "reformed" in your own practices? And does your church consider itself non-denominational or something else? Thanks so much for reading and commenting! I love thoughtful responses!

We are Reformed, and I have never heard of anyone doing this. Sure, we try to honor the Sabbath by using it as a day of rest, but I've never, ever heard of anyone this extreme. Even the Orthodox Presbyterian girls at my Reformed college still did homework on Sundays. As you said, we believe we're freed from the laws of the OT. Maintaining such a strict interpretation of the Sabbath as it is written in the OT is, well, Biblically incorrect. That doesn't mean to toss the commandments or the lessons from the OT completely out the window–you still shouldn't murder, or steal, and whatnot–but there is grace now instead of having to sacrifice an animal. And my personal argument is that if getting my laundry done is restful to me, then I'm getting my laundry done because #dayofrest (this is not a real hashtag, or at least I hope it's not!).  I'm sorry this was your experience. It sounds awful. I wouldn't want to go to that Sabbath heaven/hell either.   Also...I am not a theologian, so I really can't explain the intricacies of x, y, or z. But I just wanted to drop by and say that I've never heard of this in the PCA, PCUSA, ARP, OPC or our non-affiliated Reformed church. I'm not saying it doesn't happen, just that this extreme has never been my experience nor is it a particularly denomination-wide thing. 

The ones I know that are into Sabbath-keeping are mostly Reformed Presbyterian of various denominations, i.e. Calvinists who follow the Westminster Confession of Faith. It's a bit of an esoteric thing for sure! The RPCNA has only about 7000 members in the whole denomination, and there's variance of practice even there.  I would guess (I could be wrong) that Andrea and Kelly Reins are or were strict Sabbath-keepers, because I know the pastor of the church they attended is one.  Christian dominionists (Theocracy believers) also liked to spend time arguing about the various ways in which they thought the Sabbath should be observed. I'm talking people like Gary North (shudder). If that confused you more, I apologize. My family confused the hell out of people growing up. We got asked if we were SDA, JW, Pentecostal, or Mennonite pretty regularly, because people were trying to figure out a frame of reference for our weirdness!

So what strain of fundie is this? I never heard of such a beast outside of the fake Jews and for those people. it is not Sunday. Anyone we follow part of this?