No, Jews worship on Saturdays, Hindus and mozlums on Friday, and Christians on Sunday.
The cult this freak belongs to keeps predicting a day and time that Jesus is coming.
They are nut jobs, snake oil salesmen like the Mormons.
Where does it say in the Bible that Christians worship on Sunday or the first day?
Catholics have Sat. and Sun. mass
Well at least they don’t eat the body of Christ or drink his blood.
Christians are supposed to worship every day. Requiring Christians to keep a day as the Sabbath is not scriptural, but if you are going to make that error Saturday is at least the right day.
Romans 14:5-10 NKJV
One person esteems one day above another; another esteems every day alike. Let each be fully convinced in his own mind. [6] He who observes the day, observes it to the Lord; and he who does not observe the day, to the Lord he does not observe it. He who eats, eats to the Lord, for he gives God thanks; and he who does not eat, to the Lord he does not eat, and gives God thanks. [7] For none of us lives to himself, and no one dies to himself. [8] For if we live, we live to the Lord; and if we die, we die to the Lord. Therefore, whether we live or die, we are the Lord’s. [9] For to this end Christ died and rose and lived again, that He might be Lord of both the dead and the living. [10] But why do you judge your brother? Or why do you show contempt for your brother? For we shall all stand before the judgment seat of Christ.
Colossians 2:16-17 NKJV
So let no one judge you in food or in drink, or regarding a festival or a new moon or sabbaths, [17] which are a shadow of things to come, but the substance is of Christ.
You probably should be a Christian if you’re going to decide what makes another person Christian. We are convicted by our own words.