"And, Lo, I am with you always, even to the end of the age." (Mat. 28:20)
There is an "end of the age," and it is the end of the "age of the Gentiles" (WT muddles that fact by translating Gentiles as "nations" in the NWT, so it's definitely not as "crystal clear" in the minds of JWs).
"25 For I do not desire, brethren, that you should be ignorant of this mystery, lest you should be wise in your own opinion, that blindness in part has happened to Israel **Until** the fullness of the Gentiles has come in. 26 And so all Israel will be saved, as it is written: "The Deliverer will come out of Zion, And He will turn away ungodliness from Jacob; 27 For this [is] My covenant with them, When I take away their sins." 28 Concerning the gospel [they are] enemies for your sake, but concerning the election [they are] beloved for the sake of the fathers. 29 For the gifts and the calling of God [are] irrevocable. 30 For as you were once disobedient to God, yet have now obtained mercy through their disobedience, 31 even so these also have now been disobedient, that through the mercy shown you they also may obtain mercy. 32 For God has committed them all to disobedience, that He might have mercy on all." - Romans 11
That is basically the total summation of the "last age" which began when Israel was disobedient to the gospel, which then opened the way for the Gentiles. And when the fullness of the Gentiles have come in, God then turns His attention back to Israel as a nation. Therein lies the beginning of the final end times events.
When might that be? We cannot pinpoint the exact date, but "exact events" give us a clue as to the closeness, one big one being that Israel became a nation again (while still "blinded" as Romans 11 says) for the first time in approx. 2,500 years in 1948.
Israel is also compared to a fig tree several times throughout the OT and NT, so when Jesus said that when we see the "fig tree blossom we know summer is near," and that it would be that particular generation who will not pass away until all things occur. (Matt. 24:32-35).
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As a side note, I've always wondered how many "lunar years" have elapsed since Jesus died/Paul's conversion/missionary tours to the Gentiles, etc. So for my own curiosity, I'm going to play with some numbers in a very very very unsophisticated way (since a mathematician I am not):
2009 solar years since A.D. began
But Jesus died in/around 29 AD (?)
So subtract 29 solar years from our current 2009 = 1,980 years x 365 days per year in a solar year = 722,700 days.
A lunar year has 354 days approx., or approx. 11 days less than a solar year. So take 1,980 years x 11 days = 21,780 lunar days.
So subtract 21,780 lunar days from 722,700 solar days = 700,920 solar days, and divide that by 365 solar days for a solar year = 1,920 lunar years since Jesus died.
For my little "experiment," that means (very loosely) that God has allotted, to date, approx. 1,920 lunar years (so far) for the fullness of the Gentiles to come in.
Since most of us always round it off to an even 2,000 years since Jesus was born (A.D. began), it is more like 1,920 LUNAR years since He died (using God's time cycle/lunar years). And if we add another 12 years or so until Paul was converted (approx. 37-38 AD after which he spent 3 years in Arabia), that brings us up to 1,932 lunar years that the way has been held wide upon for the Gentiles to come in by Faith Alone (gospel of Grace and not by works as Israel was expected to do).
The reason I wondered this in the first place is because I think the Lord devoted approx. 1,500 years solely to Israel as a nation (?), so I wondered how long He might have in mind for allowing the Gentiles to come in. And if my very loose-as-a-goose lunar-year calculations are anywhere near reality, that means He has given the "mostly-Gentile Church Age" more time than He did Israel...
...Except Israel does get seven more years (one more week) of His sole "devotion" during their "Time of Jacob's Trouble" (Jer. 30:7), ie, the Tribulation.
Don't mind me, I'm just talking and figuring out loud to myself.
Even so, He IS coming again...
"I will not leave you orphans; I will come to you." - John 14:18
"In My Father's house are many mansions; if [it were] not [so,] I would have told you. I go to prepare a place for you. And if I go and prepare a place for you, I will come again and receive you to Myself; that where I am, [there] you may be also." - John 14:2,3
"You have heard Me say to you, 'I am going away and coming [back] to you. ' " - John 14:28