When carefully examining the work of the prophet Daniel and the apostle John, it appears that God reveals a specific schedule of the beginning of the end:

1. Just before the Antichrist appears, there will be a flood to harm Believers (figuratively represented as the heavenly sign of the Woman). It is not clear if this should be taken literally as a flood of water or a figure of speech as an overwhelming adverse event; Daniel uses "with a flood" figuratively to convey a sense of speed that events will unfold (Dan 9:26).

And the serpent poured water like a river out of his mouth after the woman, so that he might cause her to be swept away with the flood (Rev 12:15).

2. The 70th week of Daniel begins with the emergence of the Antichrist who, as a world leader, makes a covenant with God's people. While there is no information about this covenant, it is believed to be some sort of peaceful agreement which will last for 3-1/2 years (Dan 9:27) - perhaps preservation of the Temple while its outer courts were trampled by the nations (Rev 11:2-3).

Then the woman fled into the wilderness where she had a place prepared by God, so that there she would be nourished for one thousand two hundred and sixty days. (Rev 12:6)

And when the dragon saw that he was thrown down to the earth, he persecuted the woman who gave birth to the male child. But the two wings of the great eagle were given to the woman, so that she could fly into the wilderness to her place, where she was nourished for a time and times and half a time, from the presence of the serpent. (Rev 12:13-14)

3. Peace ends when the Antichrist desecrates the Temple, and this signals the beginning of extreme persecution of Believers, (Dan 7:25; Dan 9:27), and the start of his 3-1/2 years of evil reign and latter half of Daniel's 70th week (Rev 13:5-7).

Therefore when you see the abomination of desolation which was spoken of through Daniel the prophet, standing in the holy place (let the reader understand), then those who are in Judea must flee to the mountains. Whoever is on the housetop must not go down to get the things out that are in his house. Whoever is in the field must not turn back to get his cloak. But woe to those who are pregnant and to those who are nursing babies in those days! But pray that your flight will not be in the winter, or on a Sabbath. For then there will be a great tribulation, such as has not occurred since the beginning of the world until now, nor ever will. (Matt 24:15-21)

Leave out the court which is outside the temple and do not measure it, for it has been given to the nations; and they will tread under foot the holy city for forty-two months. (Rev 11:2)

There was given to him a mouth speaking arrogant words and blasphemies, and authority to act for forty-two months was given to him. And he opened his mouth in blasphemies against God, to blaspheme His name and His tabernacle, that is, those who dwell in heaven. It was also given to him to make war with the saints and to overcome them, and authority over every tribe and people and tongue and nation was given to him. (Rev 13:5-7)

4. While it is not explicitly mentioned but based on the purpose of Daniel's 70th week (9:24), God's judgment, commencing with His Son breaking the seals, appears to begin at the start of Daniel's 70th week when the Antichrist appears.

For deeper study:

How does Daniel’s 70th week correspond to Revelation?