If you’ve opened a date in the VedicDisha Panchang and seen something like “Tithi: Tryodashi” or “Paksha: Shukla Paksh,” this page explains exactly what those words mean, how they’re worked out, and how to read what’s shown.
What is a Tithi?
A Tithi is a lunar day — the basic time unit of the Hindu Panchang, and one of its five core elements (the other four being Vaar/weekday, Nakshatra, Yoga, and Karana). A Tithi is defined by angle, not by clock time: it’s the time it takes for the angular distance between the Moon and the Sun, measured along the ecliptic, to increase by 12°. Because the Moon’s speed varies slightly through its orbit, a Tithi isn’t a fixed length like a calendar day — it can run anywhere from about 19 to about 26 hours.
Because of this variability, a Tithi may sometimes be absent from sunrise-based calendar reckoning (a Tithi that both begins and ends between one sunrise and the next is traditionally called
kshaya or
lopa), while another Tithi may extend across more than one sunrise and get counted on two consecutive calendar days.
A full lunar month contains exactly 30 Tithis.
How Tithi Relates to the Sun and Moon
The reference point for every Tithi is the
angular separation between the Moon and the Sun — not their positions individually. At New Moon (Amavasya), the Sun and Moon are at the same longitude (0° separation). As the Moon moves faster than the Sun across the sky, that separation grows. Each time it grows by another 12°, a new Tithi begins. By the time the separation reaches 180°, the Moon is opposite the Sun — Full Moon, or Purnima. The separation then continues growing through the second half of the month, back to the next Amavasya at 360°/0°.
What is a Paksha?
A Paksha is a “fortnight” — one half of the lunar month, made up of 15 Tithis. There are two:
- Shukla Paksha (“bright/waxing fortnight”): from the day after Amavasya through Purnima. The Moon is waxing.
- Krishna Paksha (“dark/waning fortnight”): from the day after Purnima through the next Amavasya. The Moon is waning.
Each Paksha contains the same 15 Tithi names, in the same order — what differs is which Paksha you’re in, and therefore whether the Moon is growing brighter or dimmer each day.
The 15 Tithis in Each Paksha
| # |
Tithi Name |
Shukla Paksha (15th) |
Krishna Paksha (15th) |
| 1 |
Pratipada |
— |
— |
| 2 |
Dwitiya |
— |
— |
| 3 |
Tritiya |
— |
— |
| 4 |
Chaturthi |
— |
— |
| 5 |
Panchami |
— |
— |
| 6 |
Shashthi |
— |
— |
| 7 |
Saptami |
— |
— |
| 8 |
Ashtami |
— |
— |
| 9 |
Navami |
— |
— |
| 10 |
Dashami |
— |
— |
| 11 |
Ekadashi |
— |
— |
| 12 |
Dwadashi |
— |
— |
| 13 |
Trayodashi |
— |
— |
| 14 |
Chaturdashi |
— |
— |
| 15 |
— |
Purnima (Full Moon) |
Amavasya (New Moon) |
So “Trayodashi” simply means the 13th Tithi, in whichever Paksha is currently active — the VedicDisha Panchang always shows both together (Tithi name
and Paksha), so there’s no ambiguity about which half of the month you’re looking at.
Amavasya and Purnima
These two Tithis mark the turning points of the lunar month — Amavasya (New Moon) closes Krishna Paksha and opens the next Shukla Paksha; Purnima (Full Moon) closes Shukla Paksha and opens Krishna Paksha. Both carry particular significance in Hindu tradition and ritual observance, which varies by region and lineage and is outside the scope of this reference page.
How Tithi Is Shown in the VedicDisha Panchang
Opening a date’s detail popup (on the homepage or Full Year Panchang) shows a “Tithi” row and a “Paksha” row — for example, “Tithi: Tryodashi” and “Paksha: Shukla Paksh” (using the exact spelling the VedicDisha system displays, which differs slightly from the standard “Trayodashi”/”Shukla Paksha” spelling used above).
This isn’t limited to Tryodashi — many Tithi names in the live Panchang follow the same shortened pattern (for example, “Dvitya” rather than “Dwitiya,” “Panchmi” rather than “Panchami”). The 15-Tithi table above uses standard spelling throughout; the live popup may show a slightly shortened form for any of them.
What “Upto” Means
Because a Tithi doesn’t align with calendar-day boundaries, the VedicDisha Panchang shows an “until” time next to Tithi — the exact moment that Tithi ends and the next one begins. If you check the Panchang later that same day, after that time has passed, the
actual Tithi in effect will be the next one, even though the calendar date hasn’t changed.
What “Next” Means
Alongside the “until” time, the Panchang also names the
next Tithi that will begin once the current one ends — so you can see both what’s active now and what’s coming, without checking the following day separately.
Practical Takeaway
When the VedicDisha Panchang shows a Tithi and Paksha for a date, it’s telling you exactly where that day falls in the 30-day lunar month, and precisely when that will change. The “Upto”/”Next” pair is what lets you use the calendar accurately even for events that need the exact transition time, not just “today’s Tithi” in a loose sense.
Related Panchang Concepts
