Each tithi has a lord. In each fortnight the Sun rules the 1st and 9th tithi, the Moon the 2nd and 10th, Mars the 3rd and 11th, Mercury the 4th and 12th, Jupiter the 5th and 13th, Venus the 6th and 14th, Saturn the 7th and the full moon, and Rahu the 8th and the new moon. Separately, Kalaprakasika (1917, p. 183) names six Paksha-chidra tithis, the 4th, 6th, 8th, 9th, 12th and 14th, which the tradition sets aside along with Rikta. They are not the same as the Dagdha tithis, which depend on the weekday.
☕ A lord for each tithi, and three lists
Weekdays have lords: Sunday is the Sun's, Monday the Moon's. Tithis have lords too. Sanjay Rath's Crux of Vedic Astrology (p. 327) gives them in a simple cycle of eight: the Sun, the Moon, Mars, Mercury, Jupiter, Venus, Saturn and Rahu rule the 1st to the 8th tithi, and the cycle starts again at the 9th. Saturn rules the full moon and Rahu the new moon; Ketu rules none. This page gives the list as a definition only.
Kalaprakasika (1917, pp. 183–184) names six tithis “Paksha-chidra”, the gaps of the fortnight: Chaturthi, Shasthi, Ashtami, Navami, Dwadashi, Chaturdashi, that is the 4, 6, 8, 9, 12, 14. It then says: "Paksha-chidhra and Rikthai, should be avoided." The three Rikta tithis are all in the six, so the chhidra list is the wider one. The translator of Jataka Parijata gives the same six in a note (p. 824), quoting Kalaprakasika; that is the same tradition, not a second witness.
A third list works differently. A Dagdha tithi is set aside only when it falls on one particular weekday, such as Ekadashi on a Monday (Kalaprakasika, p. 206). Rikta and Paksha-chidra hold on any weekday. Nava Panchangam's day score marks the Rikta class down; it does not weigh the other three chhidra tithis or the Dagdha pairs.
Nava Panchangam does not use this rule in its day score. This page explains it as the books give it.
Lords and lists at a glance
- Sun: 1, 9
- Moon: 2, 10
- Mars: 3, 11
- Mercury: 4, 12
- Jupiter: 5, 13
- Venus: 6, 14
- Saturn: 7, full moon
- Rahu: 8, new moon
- Rikta: 4, 9, 14, on any weekday.
- Paksha-chidra: 4, 6, 8, 9, 12, 14, on any weekday; it includes all of Rikta.
- Chhidra but not Rikta: 6, 8, 12.
- Dagdha: one tithi for each weekday, only on that weekday.
Frequently Asked Questions
Which planet rules Ekadashi?
Mars. The 11th tithi is in the second round of the eight-planet cycle, after the Sun on the 9th and the Moon on the 10th.
What does chhidra mean?
A gap or an opening. Paksha-chidra means “the gaps of the fortnight”: the six tithis the tradition sets aside for starting new work.
Is a chhidra tithi the same as a Dagdha tithi?
No. The six chhidra tithis are set aside on any weekday. A Dagdha tithi counts only on its own weekday. Some Dagdha tithis happen to be chhidra tithis too, such as Navami, the Saturday Dagdha tithi.
Does the app use the tithi lords?
No. The day score weighs the tithi's class, not its lord. The lords are given here as a definition, as Rath gives them.
From the sources
The lords of all thirty tithis, and the three lists side by side.
🪐 The lord of every tithi
Restated from Rath (p. 327). The 15th tithi is the full moon in the bright half and the new moon in the dark half; Saturn rules the first and Rahu the second.
| Lord | Bright half | Dark half |
|---|---|---|
| Sun | Prathamai, Navami | Prathamai, Navami |
| Moon | Dwitiyai, Dasami | Dwitiyai, Dasami |
| Mars | Tritiyai, Ekadashi | Tritiyai, Ekadashi |
| Mercury | Chaturthi, Dwadashi | Chaturthi, Dwadashi |
| Jupiter | Panchami, Trayodashi | Panchami, Trayodashi |
| Venus | Shasthi, Chaturdashi | Shasthi, Chaturdashi |
| Saturn | Saptami, Pournami | Saptami |
| Rahu | Ashtami | Ashtami, Amavasai |
🕳️ Rikta, Paksha-chidra and Dagdha
| List | Tithis | Depends on the weekday? |
|---|---|---|
| Rikta (p. 183) | 4, 9, 14: Chaturthi, Navami, Chaturdashi | no |
| Paksha-chidra (p. 183) | 4, 6, 8, 9, 12, 14: Chaturthi, Shasthi, Ashtami, Navami, Dwadashi, Chaturdashi | no |
| Dagdha | see the dagdha page (p. 206) | yes: one tithi per weekday |
The classes are on the five tithi classes, and the weekday list on dagdha tithis.