Iyar (אִייָר or אִיָּר, Standard ʾĪyyar Tiberian ʾĪyyār; from 𒌗𒄞 itiayari "rosette; blossom") is the eighth month of the civil year (which starts on 1 Tishrei) and the second month of the Jewish religious year (which starts on 1 Nisan) on the Hebrew calendar. The name is Babylonian in origin. It is a month of 29 days. Iyar usually falls in April–May on the Gregorian calendar.
In the Hebrew Bible, before the Babylonian captivity, the month was called Ziv (, ). Ziv is a Hebrew word that means "light" or "glow".
Along with all other current, post-biblical Jewish month names, Iyar was adopted during the Babylonian captivity. In the Babylonian calendar its name was Araḫ Āru, which can be interpreted as "month of blossoming".
14 Iyar – Pesach Sheni
18 Iyar – Lag BaOmer
Fast of Behav – see Cheshvan. It is observed on the Monday, Thursday, and Monday after the first Sabbath after Rosh Chodesh Iyar. Unlike in Cheshvan, the Eastern and Western Ashkenazic rites observe it at the same time.
4 Iyar – Yom HaZikaron
5 Iyar – Independence Day (Israel)
10 Iyar – Herzl Day
28 Iyar – Jerusalem Day
1 Iyar (1788) - Death of Rabbi Menachem Mendel of Vitebsk.
2 Iyar (1834) - Birth of the Rebbe Maharash, 4th Chabad Rebbe.
4 Iyar (1165) – Maimonides survives a fierce storm at sea while fleeing from the Islamic persecution in Fez. From then on he observed the day as a personal day of fasting and prayer.
5 Iyar (1948) – Israeli Declaration of Independence on Friday, 14 May 1948, before sunset.
7 Iyar (498 BCE) – Jerusalem's rebuilt walls are dedicated nearly 88 years after their destruction by Nabû-kudurri-uṣur (Nebuchadnezzar II) of the Neo-Babylonian Empire.
8 Iyar (1096) – Rhineland massacres of the First Crusade begin – On their way to Holy Land, small bands of knights and peasants, along with local inhabitants, the "People's Crusade", attacked many Jewish communities, most notably in the Rhineland towns of Worms and Mainz. On Shabbat, 8th of Iyar, the Jews of Speyer were also attacked.