In light of OP's questions it
certainly helps to have a pattern of sound words as stated in 2 Timothy 1:13
A pattern of sound words is a word that is used consistently in scripture. Young's Translation of the word AION
is always consistently translated the same… it is defined as an age.
It does not help when you have inconsistency in words to assimilate what truth is being taught. Many Translations will translate this word aion as eternal, never, world, age lasting, course.
◄ 165. aión ►
Strong's Concordance
aión: a space of time, an age
Original Word: αἰών, ῶνος, ὁ
Part of Speech: Noun, Masculine
Transliteration: aión
Phonetic Spelling: (ahee-ohn')
Definition: a space of time, an age
Usage: an age, a cycle (of time), especially of the present age as contrasted with the future age, and of one of a series of ages stretching to infinity.
Word-studies
165 aiṓn (see also the cognate adjective, 166 /aiṓnios, "age-long") – properly, an age (era, "time-span"), characterized by a specific quality (type of existence)
Here is the same verse from second Peter 3:18 translated in two other literal translations.
Literal Standard Version
and increase in grace, and in the knowledge of our Lord and Savior Jesus Christ; to Him [is] the glory both now, and to the day of the age! Amen.
Young's Literal Translation
and increase ye in grace, and in the knowledge of our Lord and Saviour Jesus Christ; to him is the glory both now, and to the day of the age! Amen.
Christ Glory has been seen on the mount of Transfiguration by a few of His disciples, probably by some of the prophets as well as Paul and in the hearts of believers by faith.
It will truly be seen in the day
of the next age when He will be physically manifested in Glory on this earth.
Is this is not the Lord's day talked about in the previous verses?
It is also stated; remember, don't forget, Don't let it escape notice that a day With the Lord can be like a thousand years. (Emphasis on the word "with" is mine.)
But do not forget this one thing, beloved, that one day is with the Lord as a thousand years, and a thousand years as one day. 2 Peter 3:8
Could that not be the millennial of 1000 year reign with Christ?
it will come -- the day of the Lord -- as a thief in the night, in which the heavens with a rushing noise will pass away, and the elements with burning heat be dissolved, and earth and the works in it shall be burnt up. 2 Peter 3:10
The glory of Christ is coming to the earth. It is going to begin as a thief in the night, lasting for a 1000 years and ending when all the works of the earth will be exposed and burned up. That is the end of that age and will usher in the day of God, which is the new creation and another age begins. This age is often called the age of the ages.