Satan was in existence when Adam and Eve disobeyed [ ate the fruit] At Genesis 3;15 God himself states that there will be conflict between Satans 'seed' and God's 'seed' called in the Bible, the woman. Satan was not always bad, but was created an angel along with all the other angels. But he wanted worship due only to God. And in seeking it, he became Satan.
Satan was only cast out of heaven when Jesus was King of God's "Kingdom" . This happened in 1914.
How, then, is the time calculated down to 1914? Counting 2,520 years from early October of 607 B.C.E. brings us to early October of 1914 C.E., as shown on the chart.
CALCULATING THE �SEVEN TIMES�
�Seven times� = 7 X 360 = 2,520 years
A Biblical �time,� or year = 12 X 30 days = 360. (Rev. 11:2, 3; 12:6, 14)
In the fulfillment of the �seven times� each day equals one year. (Ezek. 4:6; Num. 14:34)
Early October, 607 B.C.E., to December 31, 607 B.C.E.= 1/4 year
January 1, 606 B.C.E., to December 31, 1 B.C.E. = 606 years
January 1, 1 C.E., to December 31, 1913 = 1,913 years
January 1, 1914, to early October, 1914 = 3/4 year
Total: 2,520 years
607 B,C,E, is the date that the word to rebuild Jerusalem 'went forth'. Daniel 9;25�And you should know and have the insight [that] from the going forth of [the] word to restore and to rebuild Jerusalem until Mes�si�ah [the] Leader, there will be seven weeks, also sixty-two weeks. She will return and be actually rebuilt, with a public square and moat, but in the straits of the times.