The ritual calendar used by The Ishtar Gate is a lunisolar calendar adapted from the standard Mesopotamian calendar of the 2nd millennium BCE, itself rooted in the calendar of the Sumerian holy city of Nippur.
The Sumerian calendar is principally centred around the lunar cycle, with each month starting on the day after a new moon. The moon god Nanna is also the god of the calendar, given the power to reckon the days and the months. As the moon takes 29.53 days to orbit the Earth, this yields months of 29 or 30 days. Historically, the new month would have been marked by the first observation of the new lunar crescent, but it is more common in the modern day to fix the end of each month based on astronomical calculations of the precise moment of the new moon.
It was important for the Sumerians that their calendar roughly align with the solar year, owing to the agricultural festivals celebrated throughout the year, but the primacy of the moon meant that the year must contain a whole number of lunar cycles. To harmonise the solar and lunar cycles, the final month of each year was always the one that contained the vernal equinox, after which a new year would begin.
The length of time between one vernal equinox and the next is always either 12 or 13 lunar cycles, but unlike the number of days in the month, the pattern of 'short' and 'long' years is entirely regular and predictable. 235 lunar months make up almost exactly 19 solar years, forming a repeating cycle in which years 3, 6, 8, 11, 14, 17, and 19 have 13 months, and the rest have 12. Our current cycle began in the Sumerian year that began in March 2007.
The equinoxes are the fulcrum of the Sumerian calendar, intimately tied with the agricultural routine of Mesopotamia and celebrated with lengthy and jubilant feasts in the first and seventh months. The Sumerians were aware of the solstices, but they played no great role in the reckoning of the year, with only minor festivals attested. Modern pagans may be familiar with the Wheel of the Year; this is based on the agricultural practices of northern Europe, not Mesopotamia, but Sumerian practice holds that each shrine should observe feast days as represent local need, and there is never a wrong time to offer worship and praise, so it is entirely appropriate to make offerings at solstices and cross-quarter days if they form part of your personal practice.
There are two principal observations which occur each month. The 𒀊𒀊 ešeš ("All-Shrines") festival occurs at the full moon, and is named because it is a universal holiday for Sumerians when we are all called to make a Great Offering to all of the gods of our household and observe their glory.
The Sumerians observed this by custom on the 15th day of the lunar month, although the actual time of the full moon can vary +/- 2 days. In modern practice, the actual day of the full moon, the 15th day of the month, or even your closest free day are all appropriate times if you wish to make an ešeš offering. A thoughtful offering when you have time for it is better than a rushed one when you do not.
The ešeš festival was always celebrated at the full moon; many cities recognised an ešeš on the seventh day of the month as well, at the first-quarter moon, and in later years the association of the festival with the lunar calendar grew weaker with kings and local rulers inserting them into the calendar arbitrarily.
If you intend to observe an ešeš, you can use this template for a basic ritual meal offering.
The other monthly observance is that of 𒆠𒋧𒂵 kisiga ("Funerary Offerings"), falling on the new moon (which is, by definition, the last day of the month). On this day, we hold a solemn ceremony in honour of our beloved dead, our ancestors temporal and spiritual, and the cultural spirits of our own heritage as well as the Land of Mesopotamia; the most important offering made at kisiga is a libation of fresh water, to sustain the glorious dead in the afterlife.
Kisiga is a day of mourning. We are called to mourn our dead, and know that it is right to mourn, and that we are blessed to remember them. We mourn also for the unknown dead, for the ranks of those who precede us, for all that has been fashioned by human and divine hand and then destroyed. Those who are inspired by the passions of the world's oldest civilization are also humbled by how fragmentary our records of it are - and fragmentary they are, even though we have over a million cuneiform documents. It is right, therefore, to also mourn history on kisiga - all that was, and all that never was, and all those whose names are no longer spoken.
The months of the calendar are as follows:
1. 𒌗𒁈𒍠𒃻 Barazagar
“Dais of the Sanctuary”
The Sumerian year begins with the first sunrise after the first new moon after the spring equinox, and the dais referred to in the month’s title is likely the throne dais of Enlil at the E-kur (“mountain house”) temple of Nippur. Because Nippur was Enlil’s city, his statue would have been seated on the throne of the E-kur, and the other gods and divine attendants of the city in their places of honour around him, at the New Year festival.
The New Year festival, called zagmuk (Akk. akitu) is traditionally the most important festival in the Sumerian calendar, lasting several days. It commemorates the bond between humanity and the gods, recreates the entry of the gods into their cities and dwelling places, and allows for the necessary mourning and reflection of the old year to be replaced by the hopes and ambitions of the new.
Reconstructed akitu festival for the modern practitioner
2. 𒌗𒄞𒋛𒁲 Gusisu
“Marching Forth of Oxen”
The calendars of the various city-states of Sumer were based on the local agricultural cycle and practices, with this month’s name referring to the plough pulled by the titular oxen. It marks the beginning of the agricultural season, although the actual ploughing wouldn’t begin in earnest until the fourth month; Gusisu was rather a month to select oxen for ploughing and to ensure there was sufficient agricultural equipment for the year’s work. In modern practice, we use this time to reflect on the intentions we set down in the new year and consider what resources we’ll need, and what work we must do, to manifest those intentions.
The month is particularly sacred to the god Ninurta, Lord of the Plough, who was given the honorific title Lugalgusisu (“king who directs the marching oxen”), as is the three-day ezem gusisu (“Festival of Marching Oxen”) celebrated between the 20th and 22nd of the month, culminating on the third day when Ninurta is given the highest honours.
3. 𒌗𒋞𒂵 Sig Ga
“Placing of Bricks”
The month’s name is a shortening of a longer version meaning “the month the bricks are placed in the brick mould”. With the ritual agricultural preparations of the previous month completed, attention now turned to the labour of the cities and the making of the vast quantities of mud bricks that would be vital for the new projects, rebuilding work and advances of the coming year. We therefore use this month to ensure that we are laying firm foundations and pray for righteous guidance in our new and ongoing projects and labours.
Cohen identifies no specific festival associated with this month, except the “placing of bricks” ceremony that took place at the city of Umma around mid-month, on which little further is known. However, the holy days of this month, sacred to the brick god Kulla, are an excellent time for the inauguration and renewal of projects that glorify the gods and our own creative powers.
4. 𒌗𒋗𒆰𒈾 Šunumun
Despite the name of the month, no actual planting took place at this time - the approaching brutal heat of summer meant that it was still far too early for seeding. However, this month marked the ceremonial onset of the seeding season, when the fields would be prepared by weeding and the removal of debris such as stones and the stubble of the previous harvest. It is a time to clear our minds and our personal and spiritual spaces of the accumulated detritus of the previous year, so that our way is clear for the upcoming work.
In Akkadian, this month is called Tammuz, a form of the name Dumuzi. Mythologically, Dumuzi - consort of Inana and shepherd par excellence of Mesopotamia who guarantees the fertility of the Land - is dragged to the underworld for six months of every year, as recounted in the Descent of Inana, and the fourth month of the year is a time of ritual mourning for Dumuzi and the fertility of the Earth, with his absence set to be felt most vividly with the procession of the Mesopotamian summer.
5. 𒌗𒉈𒉈𒃻 Nenegar
"Lighting of the Braziers"
The month of Nenegar represents the height of the Mesopotamian summer, when the hot sun dries and cracks the Earth and no agricultural work is possible. With the Earth lifeless, this was seen as the time when the worlds of the living and the dead were most closely connected, akin to how Halloween is seen in Western culture.
The Festival of Spirits is marked towards the end of the month. During this festival, fires and braziers are lit not only as an invitation to the spirits of the dead to return to their ancestral homes and share in a ceremonial meal, but also to drive away restless, wandering ghosts who hadn’t received adequate offerings since their passing. These offerings are not only given to the glorious dead, but also to the gods who shepherd them safely to and from the world of the living, and the chthonic deities who watch over the underworld in the same way that the gods of heaven watch over the Earth.
6. 𒌗𒆥𒀭𒈹 Kin Inana
“The Labours of Inana”
This month, as the name indicates, is sacred to Inana, and is marked by a month-long celebration and adoration of the life cycle of Inana. Beginning at the start of the month, her iconographic statue would be adorned in fine jewellery, luxurious robes and icons of divinity and authority in preparation for her visit to the temples of Enlil and Nanna, where she would be received with feasting and honour. From there, she returned to her own temple in preparation for the height of the festivities and the Great Offering given in her name at the full moon.
The second half of the month is likely a recreation of Inana’s Descent; having been adorned in all her divine powers and received the adoration of her people, she sets off for the underworld, while offerings continue to be made in her absence. On her return, around the 21st of the month, statues of her are ceremonially bathed and re-invested in their holy places in full glory, and the recreation of her life cycle continues until around the 26th with further offerings and recitations of myths that tell of how Inana won her power and glory from An, Enki and the assembly of the Anuna gods.
7. 𒌗𒇯𒆬 Duku
“The Sacred Mound"
The seventh month begins the second half of the year with its own akitu festival, as the ancients divided the solar cycle into two equinox-years. From now until the end of the year, the brutal summer heat will retreat and the conditions will be right for the gathering in of the harvest.
The Sacred Mound itself is a place in Sumerian cosmology where the earth first emerged from the primordial waters, the seat of the ancestors of the gods and the hill upon which plants and animals were first created. Its associated festival hearkens back to a time before civilisation, before writing and agriculture, and may originate in the foothills of northern Mesopotamia from which settlers first arrived at Eridu. At Nippur, it was sacred to the ancestors of the city’s god Enlil, but for worshippers in the modern day, it is appropriate to dedicate this festival to the ancestors of our personal gods and to the primordial forces of nature and fecundity representing the harshness of the nomadic struggle that the first Sumerians strove to set humans free from.
The number seven further has spiritual significance particular in later Mesopotamian tradition, and so the seventh day of the seventh month became a day to petition the gods for peace, health and vitality.
8. 𒌗𒀳𒃮𒀀 Apin Dua
“Releasing of the Plough”
The plough, having been taken down in the fourth month for the onset of the seeding season, would be put away in the eighth. Seeding is completed and the people await the harvest, making this a time to check off milestones and tie off loose ends.
Little is attested in the way of festivals related to the end of the ploughing and seeding season, although there was a custom in a cluster of cities downriver of Nippur (Ur, Isin, Larsa, Adab) of celebrating the Festival of Spirits and associated brazier festivals around the eighth month.
9. 𒌗𒃶𒃶𒈾 Gan Gan-e
“Coming of Clouds”
As sparse as rainfall is on the alluvial plain of Sumer, such clouds as were to be found in the sky would be visible during this month, which would mark the start of the growing season. It is a time of anticipation for the fruits of our labours to be revealed, keeping us focused on the path that we’ve already started walking and the themes that have marked the year for us, and exhorts us to carry on our endeavours for a major push towards the end of the year.
The translation of the month’s name is of uncertain veracity, but is in fitting with the association of the month and its corresponding “Festival of Clouds” - close to the end of the month - with the storm god Iškur.
10. 𒌗𒆬𒋆 Kusu
“Lady of the Grain”
The name of this month is most likely intended to invoke Ezina-Kusu, a grain goddess tied to a mythological cycle of Enlil, whose origins are probably to be found in Nippur and who came to be associated with Nisaba. The sight of the amber waves of grain approaching their full height would have been symbolic of the month and inspired the awe and adoration of Ezina-Kusu. No festivals are associated with the month Kusu, but it is possible to envision it as a time of preparation for the imminent harvest in a parallel to the time of preparation of the fourth month, at the same position in the equinox-year.
Kusu was the only month name to undergo a significant change in the Nippur calendar, being renamed around the rule of Amar-Suen c. 2000 BCE to 𒌗𒀊𒌓𒁺 Abbe, a festival month of deceased kings. This may encode a power struggle in and immediately after the reign of Šulgi, where Nippur - alone out of the Sumerian cities, owing to its ancient prestige - was able to resist political pressure to rename a month in its calendar after Šulgi on the occasion of the 30th year of his reign.
11. 𒌗𒍩𒀀 Uduru
With the onset of this month, the harvest season begins in earnest. Emmer and barley were the principal crops of Sumer, so it is no surprise that they lend their names to the months of the harvest season. The work of the year is coming to a close, and it's time for the ingathering of crops that will sustain us, our temples and our community over the next year.
The harvest period that begins in this month reaches its peak towards the end of the year, and meant a great deal of hard work, but work which was faced with excitement, anticipation and song for the reaping of the rewards of the year's labour.
12. 𒌗𒊺𒆥𒋻 Šekinku
"Reaping of Barley"
We come to the culmination of the year's efforts, the barley harvest, a high point of the Sumerian agricultural cycle. Barley, which adapts and grows better in the Mesopotamian soil than emmer, was preferred by Sumerian farmers, and was of vital economic importance, so its harvesting was a time of great hope and celebration.
An attested celebration, the Festival of Barley, took place around the full moon, with honour, offerings and praise given to the gods; at Nippur, this festival was principally sacred to Enlil and Ezina. It is an excellent time to give thanks for the year's growth and achievements, and to store up the legacy of the year so that it can help us further to strive in the future.
13. 𒌗𒋛𒀀𒊺𒆥𒋻 Diri Šekinku
"Second Reaping of Barley"
When the procession of the moon and the sun called for an intercalendary month to be inserted into the year, this month usually fell at the end of the year and formed part of the harvest season. (Once in every 19 year cycle, in year 17, it was instead inserted after the sixth month, and named Diri Kin Inana.)
Little is attested on ritual practice during the intercalendary month, although observations may have mirrored those of the month immediately preceding it.
Much of the calendrical information on this page is sourced from Mark E. Cohen, Cultic Calendars of the Ancient Near East (CDL Press, 1993).