The word Siroza means thirty days. As the name suggests, the Siroza Yasht is dedicated to all the thirty divine beings of the Zoroastrian calendar month, plus the three other divine beings which make up the 33 Fareshtas. Thus Siroza Yasht does not qualify either as a shorter or a larger Yasht and hence it is not enumerated in the list of Yashts.

 

Unlike the larger Yashts, Siroza Yasht does not have historical or geographical information, nor is it divided into kardehs with similar introductions and refrains. Neither it is about one particular divine being.

 

Siroza Yasht has invocations to 33 divine beings in two variations. In all, the invocations occur thrice in the Yasht. The shorter version of the invocation occurs twice and is referred to as Naani (shorter) Siroza. The larger invocation comes once and in between is referred to as Moti (larger) Siroza. The Siroza Yasht also includes the Stum no Kardo prayer.

 

The invocations from the Siroza Yasht are recited in the Siroza rituals performed on the 30^{th, 180th and 365th days after death, one day prior to Masiso, Chhamsi and Varsi prayers respectively.}

 

The tradition of remembering departed ones on the Siroza days is an ancient one. In the Pazand dibacheh it is stated:

hamā fravash ashoān yō kardehā chāhrum, dahum, siroz, sāl roz az gayomard andā soshyosh aedar yād bād. “May all righteous Fravashis, from Gayomard to Soshyos, be collectively remembered here on the fourth, tenth, thirtieth and anniversary days (of their death.)”

 

Siroza Yasht may be recited as part of the daily prayer at least once a month, preferably on the last day of the month.

 

The following 33 divine beings who are venerated in the Siroza Yasht, in the order given below. These are the Avestan forms of the 30 roj, with the other three divine beings:

1. Radiant and glorious Creator Ahura Mazda.
2. Amesha Spenta Vohu Manah who gives peace and harmony and presides over innate wisdom and acquired wisdom.
3. Amesha Spenta Asha Vahishta, along with his co-workers Airyaman, Sura and Saoka.
4. Amesha Spenta Khshathra Vairya, who is merciful and nourishes the deserving.

5 Good Spenta Armaiti, who encourages the act of giving charity with far sightedness.

6. Amesha Spenta Haurvatat who presides over Time and the timely coming of seasons.
7. Amesha Spenta Ameretatat, who gives increase in cattle and grains.

(The appropriate Geh is recited here)

8. Creator Ahura Mazda and

Amesha Spentas.

9. Adar – Fire and fire energy in six different historical and spiritual forms.
10. Aban – good waters.
11. Hvare Khshaeta – the resplendent, swiftly moving sun.
12. Māh – the moon, and Fravashi of the primordial bull and cattles.
13. Stars Tishtrya – Satavaesa, Vanant and Haptoiringa for withstanding black magic.
14. Geush Urvan – the soul of the earth along with the associate Yazad Dravāspa.
15. Creator Ahura Mazda and Amesha Spentas.
16. Mithra ruling over wide expanses.
17. Sroasha having the body of Mathra.
18. Rashnu the most upright.
19. Fravashis, vigorous, nurturing Primal and of spiritual leaders.
20. Ama – courage, Verethraghna – victory and Vanainti Uparatat – excellence.
21. Rama – joy, Vayu – atmosphere, and Time – Endless and created.
22. Beneficent, good-giving Vata – wind, and heroic Ham-vareti.
23. Creator Ahura Mazda and Amesha Spentas.
24. Upright Chishta and Den – presiding over the good Mazdayasni religion.
25. Ashi Vanghuhi, Parendi and the Divine Energies (Khvarena).
26. Arshtat – prospering the world and Mount Ushidarena
27. Asmana – the shining, luminous sky.
28. Zam Yazata, Mount Ushidarena, all mountains and the Divine Energies (Khvarena).
29. Mathra Spenta – beneficent words of prayer, Videvdad (Vendidad) – the law against evil, all laws pertaining to Zarathushtra and long standing traditions.
30. Self-created Endless Lights, Garo Nmana (the House of Songs), Misvana Gatu (the intermediate state) Chinvat Peretu (the Bridge of Selection.
31. Lord Berezat, and shining Apam Napat.
32. Golden Haoma, Haoma Frashmi who prospers the world and keeps death away.

33.Dahma Afriti, Dami Upamana Yazata and all righteous Yazatas of spiritual and corporeal worlds.