The Jewish calendar starts on the first of Nissan (April 4), according to the Torah (Exodus 12:2). What's interesting is that the new year is considered to begin in the seventh month, Tishri, at Rosh HaShanah. How can this be?
The ancient sages considered Rosh HaShanah to be when the world was made, it's the birthday of the earth. The month of Nissan marks the beginning of the Hebrew people as the Chosen of Adonai.
The 14 of Nissan is Pesach (Passover), the time God rescued the Hebrews from slavery in Egypt. It was at this time that He became their God and they became His people.
So, Nissan is the first of the year for Israel and Tishri is the first of the year for all mankind.
So, Happy New Year to God's Chosen Nation!