Baháʼí (IRST)
| Epoch | Confidence |
|---|---|
| 19 March 1844 CE +14:30:00 | High |
Overview
The Baháʼí calendar is an observational solar calendar of the Baháʼí Faith. It begins its New Year on the day of the Spring Equinox, preventing it from drifting from the tropical year and causing it to very slowly drift through the Gregorian year following the precession of the equinoxes.
It features 19 months (or sometimes referred to as weeks) of 19 days, for a total of 361 days. The remaining 4 or 5 days of each year are called Ayyám-i-Há and take place between the final two months, Mulk and 'Alá', typically at the end of February.
Days start at sunset in Tehran, which is approximated here as 18:00 IRST. Years are denoted with 'BE', meaning Baháʼí Era.
Info
The new year starts on the day that the equinox occurs before noon in Iran, or the next day if it occurs after noon. The starting of the new year results in the final month having 29 or 30 days depending on when exactly the equinox occurs.
| Month | Days | Approx. Gregorian Time |
|---|---|---|
| Bahá | 19 | Mar 21 - Apr 8 |
| Jalál | 19 | Apr 9 - Apr 27 |
| Jamál | 19 | Apr 28 - May 16 |
| 'Aẓamat | 19 | May 17 - Jun 4 |
| Núr | 19 | Jun 5 - Jun 23 |
| Raḥmat | 19 | Jun 24 - Jul 12 |
| Kalimát | 19 | Jul 13 - Jul 31 |
| Kamál | 19 | Aug 1 - Aug 19 |
| Asmá' | 19 | Aug 20 - Sep 7 |
| 'Izzat | 19 | Sep 8 - Sep 26 |
| Mashíyyat | 19 | Sep 27 - Oct 15 |
| 'Ilm | 19 | Oct 16 - Nov 3 |
| Qudrat | 19 | Nov 4 - Nov 22 |
| Qawl | 19 | Nov 23 - Dec 11 |
| Masá'il | 19 | Dec 12 - Dec 30 |
| Sharaf | 19 | Dec 31 - Jan 18 |
| Sulṭán | 19 | Jan 19 - Feb 6 |
| Mulk | 19 | Feb 7 - Feb 25 |
| Ayyám-i-Há | 4 or 5 | Feb 26 - Mar 1 |
| 'Alá' | 19 | Mar 2 - Mar 20 |
Accuracy
The accuracy of this calendar depends on the equinox calculations and may be off by a day for a whole year especially if it happens very close to sunset, but it is likely to self-correct by the next year. The equation breaks down considerably if rolled back or forward several thousand years as the equinox drifts due to precession and Terrestrial Time invokes inaccuracies.
Dates may change slightly too early or late depending on the real time of sunset.
There seems to be an issue with the stated epoch on Wikipedia being 1 day later than the calculated epoch here.
Source
A lot of the information about this calendar came from its Wikipedia article.
Dates can be referenced at the official Baháʼí website.
One of the people running the live chat at Baha'is of the United States was kind enough to provide me with their 50-year calendar, which has been used to calibrate this calendar.