Nanda, Bhadra, Jaya, Rikta, Purna: the five tithi classes
Today’s lunar date and the class it belongs to — today’s lunar date at New Delhi sunrise is Krishna Dvitiya — the 2th of its fortnight, which puts it in the Bhadra class.
A tithi is an angle, not a day
A tithi is the time the Moon takes to gain twelve degrees on the Sun. Thirty of them make a lunar month: fifteen while the gap is opening from new moon to full, and fifteen while it closes again. Because both bodies move at variable speeds, a tithi is not a fixed length — it can run as short as about nineteen hours or stretch beyond twenty-six, which is why some tithis appear to skip a calendar date entirely and others seem to occupy two.
That variability is the source of most confusion about fasting days. The convention is that the tithi in force at sunrise names the day, so a tithi that begins at nine in the morning and ends the following afternoon will label the SECOND day, not the first. A short tithi that opens and closes entirely between two sunrises is a kshaya tithi and simply does not get a day of its own.
Within the fifteen, the numbering repeats in a pattern of five groups of three. That pattern is the tithi class system, and it is one of the two or three things a person who is not an astrologer can learn and use immediately, because it explains at a glance why a family will not fix a wedding on a Chaturthi and will happily fix one on a Panchami.
The five classes and what they carry
Each class covers three of the fifteen tithis in each fortnight, and the sequence simply repeats: first, second, third, fourth, fifth belong to Nanda, Bhadra, Jaya, Rikta and Purna respectively, and then the pattern runs again from the sixth. The class assignments below are stable across traditions; the recommended uses vary a little in emphasis but not in substance.
| Class | Tithis (in each fortnight) | Lord | Sense of the name | Classically suited to |
|---|---|---|---|---|
| Nanda | 1, 6, 11 | Venus | Joy, delight | Celebration, art, ornament, festivity, beginnings of pleasure |
| Bhadra | 2, 7, 12 | Mercury | Auspicious, well-formed | Building, learning, trade, ceremony, most samskaras |
| Jaya | 3, 8, 13 | Mars | Victory | Contest, litigation, competitive undertakings, courage |
| Rikta | 4, 9, 14 | Saturn | Empty | Removal, demolition, settling debts — not beginnings |
| Purna | 5, 10, 15 | Jupiter | Full, complete | Completion, marriage, travel, the broadest of the five |
Purnima is the fifteenth of the bright fortnight and Amavasya the fifteenth of the dark; both are Purna by class, but Amavasya is separately excluded from almost every beginning, which is a good example of a specific rule outranking a general class.
Why Rikta is dropped, and when it is not
Rikta means empty, and the fourth, ninth and fourteenth are treated as days that do not hold what is placed in them. That is why nearly every occasion profile on this site excludes them outright: a marriage, a house entry, a first tonsure, an incorporation, a lease all want a day that keeps its shape. The exclusion is one of the least controversial rules in the whole literature.
The exceptions are instructive because they are not arbitrary. Acts whose whole purpose is REMOVAL rather than establishment can take a Rikta day and are sometimes preferred on one: demolition, clearing, closing an account, ending an arrangement, and in some readings certain medical procedures whose intent is excision. An empty day suits an emptying act. This is the same logic that lets the sharp nakshatras, barred everywhere else, be the correct stars for a surgeon.
One more carve-out is worth knowing because it catches people out. Specific festival tithis override the class: Ganesh Chaturthi is a Chaturthi, Maha Shivaratri falls on the fourteenth of the dark fortnight, and Anant Chaturdashi on the fourteenth of the bright. These are observances, not elections, and a devotional day is not a muhurat — the class rule is about choosing when to begin something, not about when to worship.
Using the classes without over-using them
The classes are a fast first filter and a poor final answer. They rank the fifteen positions of a fortnight against each other and nothing more; they say nothing about which fortnight, which month, or which star. A Purna tithi in a barred solar month is still barred, and a Bhadra tithi under a fierce nakshatra is still a date most traditions would set aside for a beginning.
They also interact with the paksha in a way that is easy to miss. Most beginnings prefer the waxing fortnight, when the Moon is gaining light, so the strongest ordinary dates in practice are the Bhadra and Purna tithis of the shukla paksha — the second, fifth, seventh, tenth, twelfth and thirteenth. That is not a separate rule so much as two rules landing on the same days, which is why those numbers recur so often in printed muhurat lists.
The site applies exactly that arithmetic. Each occasion declares the tithis it favours, the Rikta bar is on by default and lifted only for the acts that classically reclaim it, and Amavasya is excluded separately. What no tithi rule can do is tell you whether the resulting date suits your chart — that check counts from your own birth star, not from the fortnight.
Frequently asked questions
Why does my calendar show two days with the same tithi?
Because that tithi was in force at sunrise on both days. A tithi can run past twenty-six hours, and when it begins shortly before one sunrise and ends shortly after the next, both days are labelled with it. The mirror case also happens: a short tithi that opens and closes between two sunrises gets no calendar day at all and is called a kshaya tithi.
Is Amavasya always inauspicious?
Not in itself — it is the appointed day for ancestral rites, for several important observances, and Diwali’s main puja falls on one. What it is not suited to is BEGINNING something, because the Moon carries no light, and that is the sense in which muhurat texts exclude it. The distinction between a devotional day and an electional one does a lot of work here.
Related guides
How this guide is maintained
Everything computed on this site â the sunrise and sunset behind every window on this page, and the tithi, nakshatra, yoga and karana behind the date tables â comes from a Lahiri sidereal ephemeris and a NOAA sunrise model applied to the exact coordinates of the city shown, with New Delhi as the reference city for anything not city-specific. Where this guide describes a rule that genuinely varies between texts, regions or family traditions, it says so in the paragraph rather than picking a side quietly, and where the site’s own date scorer takes a documented shortcut, the shortcut is named.
What no guide on this site can do is weigh your own chart. The tables here are a panchang shortlist — the classical tests a calendar can settle — and the personal layer that decides between the surviving dates is a separate step. Start with the occasion pages for computed dates, and see how we compute muhurat for the full method.
Written and maintained by Savan Vyas. A rule applied wrongly here is a bug, and corrections are genuinely welcome.
For a full personalised muhurat matched to your own birth chart, ask Soma on AskSoma.