>>846265
Yes it's simply a cult offshoot. Just like catholicism, we can say this:
Mark 7:
> 7 Howbeit in vain do they worship me, teaching for doctrines the commandments of men.
> 8 For laying aside the commandment of God, ye hold the tradition of men, as the washing of pots and cups: and many other such like things ye do.
> 9 And he said unto them, Full well ye reject the commandment of God, that ye may keep your own tradition.
And as someone else pointed out, Colossians 2:16-17 and Romans 14 more specifically refutes a doctrine of special calendars:
Colossians 2:
> 16 Let no man therefore judge you in meat, or in drink, or in respect of an holyday, or of the new moon, or of the sabbath days:
> 17 Which are a shadow of things to come; but the body is of Christ.
Romans 14
> 5 One man esteemeth one day above another: another esteemeth every day alike. Let every man be fully persuaded in his own mind.
[…]
>13 Let us not therefore judge one another any more: but judge this rather, that no man put a stumblingblock or an occasion to fall in his brother's way.
> 14 I know, and am persuaded by the Lord Jesus, that there is nothing unclean of itself: but to him that esteemeth any thing to be unclean, to him it is unclean.
IOW, SDA separate themselves from the church over the fact of keeping doctrines of men. In this case, Judaizers, who try to reinforce some part of the Old Testament law, and in doing so refuse in their mind to accord Jesus Christ the honor of fulfilling the Law, as it is so spelled out plainly. Just as the Judaizers continued to sacrifice animals in rebellion to Christ as described in the book of Hebrews. As Paul said in Colossians, the sabbath days were a shadow of things to come. They can't point you to a Scripture basis for their special calendar then, which someone made up at some later date to this and that they treat as if it was a doctrine of God when it is really a commandment of men, not found in the Bible.
>>846261
Nobody is saying you can't keep your own calendar for your own personal use only. It goes against Scripture to Judaize by imposing non-Biblical commandments of men. That's sort of the point. They try to get in the door by making you follow some kind of law they made up. To do this, they might also pretend there's a scripture basis for it when there's really not. And as the other anon pointed out, they have much bigger problems if you look at their other strange doctrines made by the same people.