According to Hadees of prophet as narrated by Sheijh Imran Hosein
Dajjal was given 40 days rule from Allah, where
1 day will be like a heavenly year (1000 earlthy years)
1 day will be like a heavenly month (1000/12=82.5 years)
1 day will be like a heavenly week (82.5/4= 21 years)
And the rest of the days will be like earthly days.
We believe that Dajjal cannot start his rule until there is a rahbar(guider) physically present on earth.
If you follow the family of prophets who were the religious successors (not political) they were known as Imams and there are 12 of them.
The final imam with the name Mahdi went into occulation in
Considering Dajjal was released then, let's calculate
Now 1 day like 1 heavenly year started
1 heavenly year = 1000 earth years
So from 948-1948 if you see Britain gained and became the super power on earth.
He started his rule from there
Suddenly between 1930-1948 Britain started weaking and US became a super power with introduction of Atom bomb
So he shifted his rule from UK to US SLOWLY
1948 se 1 day like 1 heavenly month started
1 hm = 83 years
So 1948 - 2031 period US would be a super power. Next he needs to make a move into Jerusalem...
You will notice that in the early 2000s suddenly Israel became a super power and started fighting Palestine for Jerusalem.
So my belief is that between 2021 - 2031 rule of 1 day like a week rule will start.
1 heavenly week = 21 years
2021-2041 or 2031-2041 Israel will dominate the world and it will become the super power and after that period he will come down to appear visually and continue the rest of the days as earthly days.
Why emphasize so much on Jerusalem is due to the fact that everyone knows Jesus is the true messiah and will have a rule established from Jerusalem. But the name Dajjal means "Deciever" and he will claim to be the false messiah. Any guess how he can make the world believe that he is the true messiah?
When the world is in crisis he will come to Jersusalem and perform magic claiming to be the true messiah. He will restore lands that have withered, provide water and every other possible tricks to deceive true believers. He will even have the power to bring back people to life but the issue is that he can bring back a person to life only once not multiple times. That's where we can identify him.
After this, the arrival of Mahdi and the true Messiah will occur and a war will occur post which peace will be restored until Day of Judgement.