I don't know for sure how the mark was manifested and at what time frame it was in (other than the 1st century). John relates it but it does not appear in any of the gospels or other letters. So attempting to explain it is not something I really concern myself with.
But if you want to delve into revelation look at what Jesus said about "mountains fall on us" and what John stated in his revelation:
(Luke 23:28 But Jesus turning unto them said, Daughters of Jerusalem, weep not for me, but weep for yourselves, and for your children.)
(Luke 23:29 For, behold, the days are coming, in the which they shall say, Blessed are the barren, and the wombs that never bare, and the paps which never gave suck)
(Luke 23:30 Then shall they begin to say to the mountains, Fall on us; and to the hills, Cover us.)
John in his revelation:
(Rev 6:12 And I beheld when he had opened the sixth seal, and, lo, there was a great earthquake; and the sun became black as sackcloth of hair, and the moon became as blood)
.
.
(Rev 6:16 And said to the mountains and rocks, Fall on us, and hide us from the face of him that sitteth on the throne, and from the wrath of the Lamb)
(Rev 6:17 For the great day of his wrath is come; and who shall be able to stand?)
John specifically uses the "fall on us" motif of Jesus with the women of Jerusalem which indicates the sixth seal was in the women's lifetime.
(Rev 1:1 The Revelation of Jesus Christ, which God gave unto him, to show unto his servants things which must shortly come to pass; and he sent and signified it by his angel unto his servant John)
But if you want to delve into revelation look at what Jesus said about "mountains fall on us" and what John stated in his revelation:
(Luke 23:28 But Jesus turning unto them said, Daughters of Jerusalem, weep not for me, but weep for yourselves, and for your children.)
(Luke 23:29 For, behold, the days are coming, in the which they shall say, Blessed are the barren, and the wombs that never bare, and the paps which never gave suck)
(Luke 23:30 Then shall they begin to say to the mountains, Fall on us; and to the hills, Cover us.)
John in his revelation:
(Rev 6:12 And I beheld when he had opened the sixth seal, and, lo, there was a great earthquake; and the sun became black as sackcloth of hair, and the moon became as blood)
.
.
(Rev 6:16 And said to the mountains and rocks, Fall on us, and hide us from the face of him that sitteth on the throne, and from the wrath of the Lamb)
(Rev 6:17 For the great day of his wrath is come; and who shall be able to stand?)
John specifically uses the "fall on us" motif of Jesus with the women of Jerusalem which indicates the sixth seal was in the women's lifetime.
(Rev 1:1 The Revelation of Jesus Christ, which God gave unto him, to show unto his servants things which must shortly come to pass; and he sent and signified it by his angel unto his servant John)
So following your reasoning in https://www.biblegateway.com/passage/?search=Isaiah+13:4-6&version=KJV do you think the day of the Lord came when Isaiah said that also?