I might be mistaken, but I don’t believe Mass can be held on Holy Saturday anytime prior to dusk, unless there are sufficiently grave reasons to require it anda dispensation is obtained.
Casslean is correct. There wouldn’t normally be a 4pm Mass for Easter.
As Paschalis Sollemitatis states:
“The entire celebration of the Easter Vigil takes place at night. It should not begin before nightfall; it should end before daybreak on Sunday.”[82] This rule is to be taken according to its strictest sense. Reprehensible are those abuses and practices which have crept into many places in violation of this ruling, whereby the Easter Vigil is celebrated at the time of day that it is customary to celebrate anticipated Sunday Masses.[83]
You keep asking questions about whether Masses “count” for the Sunday obligation. The answer is always the same: you can fulfill your obligation by attending Mass that day or the evening before. This is why Catholic parishes offer Mass the evening before a Sunday or holy day. Is there some reason you have doubts about your parish or the knowledge of your priests in making up the Mass schedule?
Most parishes will cancel their 4 or 5pm Sat Mass on Holy Saturday due to holding the Vigil late. My local parish starts the Vigil Mass at 8:30 next Saturday evening. One new member coming into the Body of Christ. Amen.
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