Av is the fifth month of the Hebrew calendar counting from Nisan, thirty days that always land in July and August, the middle of summer. It is the month Jewish national memory is concentrated in: Tisha B'Av, the date on which both Temples were destroyed, sits in its first third. But Av is not only a month of mourning. Six days after the fast comes Tu B'Av, which the Mishnah ranks among the two best days Israel ever had.
No other month in the calendar travels that far inside thirty days. The Mishnah sums up its first half in three words: “when Av enters, we reduce our joy” 1. It describes the second half with dancing in the vineyards.
The fifth month
The name Av came back from Babylon with the returning exiles, like every Hebrew month name in use today. In the Bible the month is known only by its number, “the fifth month”, and that is how Zechariah refers to the fast inside it as well: “the fast of the fifth” 2.
The one day the Torah dates explicitly to this month is the death of Aaron the priest: “Aaron the priest went up Mount Hor at the command of the Lord and died there… in the fifth month, on the first of the month” 3. It is the only death in the entire Torah given a calendar date, and it falls exactly on Rosh Chodesh Av.
The stretch leading to the fast is called bein hametzarim, “between the straits”. It opens back on the 17th of Tammuz and runs twenty-one days, and the phrase comes from Lamentations: “all her pursuers overtook her between the straits” 4, a narrow pass, a place with nowhere to turn. From Rosh Chodesh Av onwards those days are known as the Nine Days, the most concentrated part of the period.
The days of Av, in order
Rosh Chodesh Av (1 Av). A single day, because Tammuz always has twenty-nine. It opens the Nine Days, in which joy is deliberately scaled back until the fast.
Tisha B'Av (9 Av). The Jewish people's national day of mourning and, alongside Yom Kippur, the longest fast of the year, marking the destruction of both Temples. When the 9th lands on Shabbat, the fast moves to Sunday.
Shabbat Nachamu. The first Shabbat after the fast, named for its haftarah opening “Comfort, comfort my people”. It begins a run of seven Sabbaths of consolation that reaches Rosh Hashanah, and in Israel it is also the weekend the whole north fills up.
Tu B'Av (15 Av). The day the Mishnah places at the head of the year's good days, next to Yom Kippur. In modern Israel it is the festival of love, and one of the most sought-after dates in the wedding calendar.
30 Av. The last day of the month, and already the first day of Rosh Chodesh Elul. From here the run-up to Rosh Hashanah begins.
The vineyards of Tu B'Av
The surprising thing about Tu B'Av is not that it is joyful but how high the Mishnah places it: “Israel had no days as good as the fifteenth of Av and Yom Kippur” 5. Two days a year, side by side, the gravest and the happiest.
And what did people do on it? The daughters of Jerusalem went out to dance in the vineyards “in borrowed white garments”. All in white, and all in clothes belonging to someone else, including those who owned a dress of their own. The reason is given on the spot: “so as not to shame anyone who had none” 5.
That detail is what turns a description into a story. The great celebration of the year was not built around those who had, but around those who did not, and on that day, out in the field, you could not tell which was which. Six days after this people wept over what it had lost, it went out dancing in borrowed clothes.
A month that falls and rises
What makes Av a single month rather than a fast and a festival that happened to land in the same thirty days is the direction it moves in. It opens by scaling down, bottoms out on the ninth, and from there starts climbing: Shabbat Nachamu, and then Tu B'Av.
The prophet Zechariah said as much outright, gathering all four fasts of the destruction into one line: “the fast of the fourth, the fast of the fifth, the fast of the seventh and the fast of the tenth shall become joy and gladness for the house of Judah” 2. Not that the fast would be cancelled: that the fast itself would turn. The fast of the fifth on that list is Tisha B'Av.
Which is, in the end, what Av describes: not only the memory of a catastrophe, but a month built so that the climb begins the moment the fall ends. In modern Hebrew it sounds almost secular: August, school holidays, weddings in vineyards, but the order was set two thousand years ago.
Common questions about the month of Av
When is Rosh Chodesh Av?
On the 1st of Av (24/7/28), and for a single day only. Rosh Chodesh runs two days when the preceding month is full, but Tammuz always has twenty-nine, so Av gets the short version. The Nine Days begin from that day.
When is the eve of Rosh Chodesh Av?
On the 29th of Tammuz (23/7/28), the last day of that month.
How many days are in Av?
Thirty, always. Av is one of the fixed-length months of the Hebrew calendar; it does not vary between a full and a deficient year.
What are the observances of the month of Av?
Rosh Chodesh Av at the start (on 24/7/28), Tisha B'Av on the ninth (on 1/8/28), Shabbat Nachamu after it, and Tu B'Av in the middle of the month (on 7/8/28). Some of them have a page with dates and times; the grid above shows how they sit together inside one month.
When does Av end?
On the 30th of Av, which is already the first day of Rosh Chodesh Elul (22-23/8/28). The next day is the 1st of Elul, the last month of the Hebrew year.
An Av calendar: the Hebrew and civil dates side by side
The grid at the top of this page shows Av as the Hebrew calendar sees it: the large numerals are the days of the Hebrew month, with the corresponding civil date printed beneath each one. You can see at a glance which civil date the 1st of Av falls on in the year selected and which weekday it is, and from there where the ninth and the fifteenth land.
Because Av always falls between late July and early September, a civil calendar splits it across two months. Here it appears as one unit. The button above the grid prints it to a single page, portrait or landscape, without the navigation or this text.
- Every observance of the year in one table, and from there each one's own page: Jewish holidays 2026
- The full printable calendar: printable 2026 Jewish calendar with holidays
- For a civil-month view, in which July and August appear separately: Gregorian month calendar
Related pages
References
- Mishnah Ta'anit 4:6 מסכת תענית פרק ד׳, משנה ו
Five things happened to our forefathers on the seventeenth of Tammuz and five on the Ninth of Av… On the Ninth of Av it was decreed upon our ancestors that they would not enter the land, and the Temple was destroyed the first time and the second, and Beitar was captured, and the city was plowed. From when Av begins, we decrease rejoicing.
source - Zechariah 8:19 זכריה פרק ח׳, פסוק יט
Thus said the God of Hosts: The fast of the fourth month, the fast of the fifth month, the fast of the seventh month, and the fast of the tenth month shall become occasions for joy and gladness, happy festivals for the House of Judah; but you must love honesty and integrity.
source - Numbers 33:38 במדבר פרק ל״ג, פסוק לח
Aaron the priest went up Mount Hor at the command of the Lord and died there, in the fortieth year after the Israelites left the land of Egypt, in the fifth month, on the first of the month.
source - Lamentations 1:3 איכה פרק א׳, פסוק ג
Judah has gone into exile because of misery and harsh oppression; she dwelt among the nations and found no rest — all her pursuers overtook her between the straits.
source - Mishnah Ta'anit 4:8 (statement of Rabban Shimon ben Gamliel) מסכת תענית פרק ד׳, משנה ח
Israel had no days as good as the fifteenth of Av and Yom Kippur, on which the daughters of Jerusalem would go out in borrowed white garments — so as not to shame anyone who had none.
source