In order to understand the Bible better, it helps to know the Jewish calendar. They had developed a calendar that was changed in the time of Moses. This site shows the old and new calendars.
Exodus 12:2 "Now the LORD spoke to Moses and Aaron in the land of Egypt, saying, This month shall be your beginning of months; it shall be the first month of the year to you."
Hebrew Months | Old | New | English Months |
Tishri (Ethanim) | 1 | 7 | Sept. - Oct. |
Cheshvan (Bul) | 2 | 8 | Oct. - Nov. |
Chisleu | 3 | 9 | Nov. - Dec. |
Tevet | 4 | 10 | Dec. - Jan. |
Sh’vat | 5 | 11 | Jan. - Feb. |
Adar | 6 | 12 | Feb. - Mar. |
Nisan (Aviv) | 7 | 1 | Mar. - Apr. |
llyar (Zif) | 8 | 2 | Apr. - May |
Sivan | 9 | 3 | May - June |
Tammuz | 10 | 4 | June - July |
Av | 11 | 5 | July - Aug. |
Elul | 12 | 6 | Aug. - Sept. |