I know that to the Jews the Jewish Sabbath, on Saterday, is from sundown to sundown. Does this apply to the Lord’s day also? Thanks and God bless.
Yep… which is why we can have Saturday vigil masses and Sunday night masses to fulfill our Sunday and holy day obligations.
More than that, we also have two different Evening Prayers for each Sunday in Liturgy of the Hours, reflecting that Saturday evening as traditionally been reckoned the start of the Sabbath
Technically, no, I don’t believe that it does. We reckon our days according to the Roman system, midnight to midnight, which is why we may assist at Mass at any time on Sunday. However, the Church also has the power of binding and loosing, and it is equally fitting that we anticipate our Lord’s resurrection, and so we may assist at the Saturday vigil Mass to fulfill our Sunday privilege. Notice that the Saturday Mass is a vigil, thereby implying that what we are celebrating has not yet occured, and so it is not Sunday.