The women that followed Jesus kept the Sabbath of the Ten Commandments (the weekly Seventh Day Sabbath, Saturday). Note also this is after the death of Jesus, showing it was still valid:
And the women also, which came with him from Galilee, followed after, and beheld the sepulchre, and how his body was laid.
Luke 23:55,56
And they returned, and prepared spices and ointments; and rested the sabbath day according to the commandment.
Paul and John were Jewish and both kept the Saturday Sabbath (Friday sundown to Saturday sundown):
And on the sabbath we went out of the city by a river side, where prayer was wont to be made; and we sat down, and spake unto the women which resorted thither.
Acts 16:13
I was in the Spirit on the Lord’s day, and heard behind me a great voice, as of a trumpet,
Revelation 1:10