Only God knows how and when time will end

Mark 13:20, 32-33

Unless the Lord had shortened the days, no flesh would have been saved; but for the sake of the chosen ones, whom he picked out, he shortened the days. But of that day or that hour no one knows, not even the angels in heaven, nor the Son, but only the Father. Watch, keep alert, and pray; for you don’t know when the time is.