Was the first day of the week also called the Lord's day?

[TonyChanYT]

Disclaimer: Please note that this OP/thread is NOT about the Sabbath. I assume that the Sabbath is on Saturday. See Should we keep the Sabbaths?.

Apostle John mentioned "first day" in John 20:

20 Now on the first day of the week Mary Magdalene came to the tomb early, while it was still dark, and saw that the stone had been taken away from the tomb.

Later, the same John also mentioned "Lord's Day" in Revelation 1:

10 I was in the Spirit on the Lord’s day, and I heard behind me a loud voice like a trumpet.

Was the first day of the week also called the Lord's Day?

NT alone does not say that explicitly.

Outside Scripture, Didache 14:

But every Lord's day gather yourselves together, and break bread, and give thanksgiving after having confessed your transgressions, that your sacrifice may be pure.

Wiki:

Didache 14 was apparently understood by the writers of the Didascalia and Apostolic Constitutions as a reference to Sunday worship.
Around 110 AD, St. Ignatius of Antioch used "Lord's" in a passage of his letter to the Magnesians. ...
In the expanded version of Magnesians, this passage to make "Lord's Day" a clear reference to Sunday, as Resurrection Day.

I think the Lord's Day was more likely the first day of the week than any other day of the week.

 

[mailmandan]

The Lord's Day - Revelation 1:10 ... The First Day!