Pope Sylvester I Transfered the Sabbath to Sunday

Pope Sylvester first among the Romans ordered that the names of the days [of the week], which they previously called after the name of their gods, that is, [the day] of the Sun, [the day] of the Moon, [the day] of Mars, [the day] of Mercury, [the day] of Jupiter, [the day] of Venus, [the day] of Saturn, they should call feriae thereafter, that is the first feria, the second feria, the third feria, the fourth feria, the fifth feria, the sixth feria, because that in the beginning of Genesis it is written that God said concerning each day: on the first, "Let there be light:; on the second, "Let there be a firmament"; on the third, "Let the earth bring forth verdure"; etc. But he [Sylvester] ordered [them] to call the Sabbath by the ancient term of the law, [to call] the first feria the "Lord's day," because on it the Lord rose [from the dead], Moreover, the same pope decreed that the rest of the Sabbath should be transferred rather to the Lord's day [Sunday], in order that on that day we should rest from worldly works for the praise of God.

Odom, Robert L., Sabbath and Sunday in Early Christianity, Review and Herald Publishing Association, 1977, pp. 247-248.