You must still feel guilt over that.
It’s a funny thing, this obsession over a day of the week, when the commandments never mention a day of the week. Nor do they mention a day of worship.
They do say that Israelites should work no more than 6 days in a row and then rest for a day, for a sabbath. This I think makes the sabbath a personal day. If not, then you might end up working more than 6 days in a row.
Consider that if you travel west and every 7th day you take a break - take a sabbath - and keep traveling west until you arrive back home - you’ll be a day behind. If you then continue working until the people you left behind have worked their 6 days and then take a sabbath with them you’ll have worked 7 days in a row. Oops. So, did you break the commandment? I think you did!
Also, if you use the biblical definition of a day, from sunrise to sunrise, and you happen to live in the far north or far south, you’ll spend months without a sabbath, both in the dark season and the light season. But I guess that’s OK, since the sun didn’t rise from your horizon…
If you consider the various outlying examples like this, the whole thing become a quagmire. IMO, like so many other things, it’s better to go by the spirit of the law - take a break from toiling on a regular basis to contemplate and remember what you have been blessed with.
If you want do use a pagan calendar to do this, fine.