How Our Calculators Work
Last updated: 2026-08-22
Example: one real birth date
On January 21, 2024 the sun-sign tool returns Aquarius. The Indian Vedic Moon tool, with no birth time, returns Vrishabha rashi, nakshatra Rohini, pada 3.
The rising tool stays blank until a time and city are added. The Chinese tool returns the Year of the Water Rabbit. Each section below is the limit of that one tool, checked against this date.
Enter your own date on the Zodiac Sign Calculator.
Almost every calculator on Today's Horoscope runs on our servers. The daily zodiac challenge is the exception. This page gathers the same "How we calculate" notes from each tool. You will see the inputs, calendar rules, and outputs. You will also see what we do not claim.
Today's Horoscope
Your day across seven traditions. We show what they share and where they differ.
You enter a birth date. Time and city are optional, but they help with Moon and rising. The app builds daily, weekly, and monthly readings using each tradition's own rules. Those rules cover Western sun, Indian Vedic Moon (Lahiri sidereal), and Chinese year animal (Lunar New Year). They also cover Mayan Tzolk'in (Maya 260-day calendar) day-sign, Celtic tree month, Akan weekday soul, and Tibetan Losar (Tibetan New Year) animal year.
When traditions share a theme, we note that. When they focus on different things, we say that too. Results are generated on our servers.
- Input: birth date required. Time and city help Moon, rising, and nakshatra.
- Sources: calendar tables that match our learn guides
- Output: seven tradition cards plus shared and different themes for the day.
Zodiac Sign Calculator
Your Western sun sign with element, modality, and ruler.
Your birth date maps to a Western sun sign using standard month and day ranges (Capricorn through Sagittarius). We also show element, pace, and ruling planet. Pace means cardinal, fixed, or mutable.
This is the same sun-sign logic used on the home reader's Western card. If your birthday is near a cusp, birth time helps when you try the Moon and rising tools.
- Input: birth date (mm/dd/yyyy)
- Calendar: tropical zodiac solar months
- Output: sign name, symbol, element, modality, ruler
- Not a full natal chart, no houses, aspects, or progressions
Moon Sign Calculator
Indian Vedic Moon rashi and nakshatra from your birth date and time.
Indian Vedic Janma Rashi comes from sidereal Moon position using the Lahiri ayanamsa. Ayanamsa is the offset between tropical and sidereal zodiacs. Sidereal means star-based. With only a date, we estimate the Moon at local noon. Birth time and city work better near rashi or nakshatra boundaries.
When the Moon position is clear, we also show nakshatra and pada (quarter). This matches the Indian Vedic card in the seven-tradition reader.
- Input: birth date; time and city strongly recommended
- Source: Lahiri sidereal math in the app
- Output: Moon rashi, nakshatra, and pada when available
- Different from tropical Western Moon or sun sign
Rising Sign Calculator
Indian Vedic Lagna, or ascendant, when you have birth time and place.
Rising sign (Lagna / ascendant) needs birth date, exact time, and place. We estimate sidereal Lagna from your city and time zone when all three are present.
If time or location is missing, we leave rising blank instead of guessing.
- Input: date, time (hh:mm), and city from the picker
- Method: sidereal ascendant estimate (Lahiri), Western sign names
- Output: Lagna label and short note, or nothing if data is incomplete
Chinese Sign Calculator
Open Chinese Sign Calculator →
Your Sheng Xiao year animal and element from birth date.
Chinese year animal comes from your birth year, but we adjust for Lunar New Year. Born in January or early February? You might still be last year's animal.
Each year also gets an element color (Wood, Fire, Earth, Metal, Water) on the same twelve-year loop you see on our Chinese tradition card.
- Input: birth date only
- Switch-over: Lunar New Year (late Jan to early Feb), not Jan 1
- Output: year animal, element, and combined label
- Same engine as the Chinese card on the home reader
Tzolk'in Calculator
Your Mayan Tzolk'in day-sign (nawal) and tone from birth date.
Mayan day-sign uses a simplified Tzolk'in (Maya 260-day calendar) count. Your birth date gives you one of twenty nawales plus a tone from 1 to 13.
This matches our Mayan card on the home reader. Living Maya communities may count days differently.
- Input: birth date only
- Calendar: 260-day Tzolk'in (20 × 13) day-count
- Output: tone, nawal name, and short description
Celtic Tree Zodiac Calculator
Open Celtic Tree Zodiac Calculator →
Your Celtic tree sign, or Ogham tree moon, from birth date on the solar year.
Celtic tree sign assigns a tree month from your day of year on the solar calendar. Birch through Elder across the year.
This is a modern seasonal story used in our reader. It is not a claim about historic druid practice.
- Input: birth date only
- Calendar: solar year split into tree months
- Output: tree name and short description
- Fixed to your birthday, does not change each year
Akan Day Name Calculator
Open Akan Day Name Calculator →
Your Akan day name and day-soul (kra) from the weekday you were born.
Akan day-soul (kra) follows the weekday of your birth: Kwasi (Sunday) through Kwame (Saturday). Stories also add a short domain note.
We use the calendar date you enter. Births right at midnight are best checked with family custom.
- Input: birth date only
- Source: weekday-of-birth mapping (Akan kra names)
- Output: day-soul name, weekday, and domain note
Tibetan Sign Calculator
Open Tibetan Sign Calculator →
Find which Tibetan zodiac sign you are from your birth date.
Tibetan birth-year animal uses a twelve-year cycle with Wood, Fire, Earth, Iron, or Water. The animal changes at Losar (Tibetan New Year), not January 1. We use Losar date tables for late-winter births.
Full Tibetan charts can also include mewa numbers and weekday deities. This tool sticks to the birth-year animal you see on the home reader.
- Input: birth date only
- Boundary: Losar date table (late Jan–early Mar), not Jan 1
- Output: animal, element (Iron not Metal), combined label
- Related to but not the same as Chinese Sheng Xiao
Horoscope & Zodiac Compatibility - Indian Vedic, Chinese & Western
Open Horoscope & Zodiac Compatibility - Indian Vedic, Chinese & Western →
Astrology compatibility across Western, Chinese, and Indian Vedic pairing, plus every sun-sign match.
You enter two birth dates. Western themes use tropical sun signs, elements, and modality. Chinese Sheng Xiao (Chinese year animal) compares year animals with a Lunar New Year cutoff. Indian Vedic Ashtakoota (Indian Vedic pairing points) compares Moon nakshatra and rashi across eight kootas when time and city allow.
The three panels can disagree. That is expected.
- Input: your birth date plus a partner birth date
- Indian Vedic: time and city on both charts when you want full Ashtakoota
- Output: three reference panels