How to use the joshiastro tools
The joshiastro tools calculate the panchang, the birth chart, the Vimshottari dasha, a muhurat finder and chart checks. Each runs in the browser and states its method.
What it is
Enter the date, time, city or coordinates, UTC offset and ayanamsa. Read the results with the method note beside each tool, and check the limits stated in each article before drawing conclusions.
How it is worked out or read
The tools do not store your details. Results can be reproduced by entering the same values, and the method page gives the formulas for anyone who wants to check them.
Where it appears on this site
Start at the tools page. The 30-day reading plan is a good next step for new users.
The birth chart
The birth chart tool asks for the date, the time, the place and the UTC offset in force at birth, and lets you choose the ayanamsa: Lahiri, Raman or KP. You can pick a city from the list or type a latitude and longitude for any place. The result shows the Lagna and the nine grahas with their sign, degree, nakshatra, house and whether each is retrograde, followed by a list of the twelve whole-sign houses with the planets in each, and a check of nine standard yogas, each with the rule it was tested against.
For births outside India, look up the UTC offset for the date, including any daylight saving, before entering it.
The panchang
The panchang tool gives the five limbs for any date at sunrise in a chosen Indian city: tithi, vara, nakshatra, yoga and karana, together with the Moon sign, sunrise and sunset, and the times when each value changes within the following day and a half. It also gives the day's Rahu Kaal and Abhijit window. The ayanamsa is your choice, and the page states which one was used.
The muhurat finder and the dasha timeline
The muhurat finder searches a range of up to 62 days for days whose sunrise nakshatra and weekday match the ones you tick. It does not decide which values suit a purpose; that is left to you and your tradition, and the articles on muhurat explain the common lists. The dasha tool gives the full 120-year Vimshottari timeline from the Moon's nakshatra at birth, with each mahadasha and its antardashas and their start dates.
The chart checks
The chart checks tool tests three widely discussed conditions: Manglik dosha from Mars, Kaal Sarpa, and Sade Sati. For each it shows whether the rule is met and why, so that the reasoning is visible. The accompanying articles explain the variations between traditions and the cautions that apply to each of these conditions, which are often presented more alarmingly than the texts justify.
Good habits with the tools
Check the birth details before reading anything: date, time with AM or PM, place, and UTC offset. Note which ayanamsa you used, and keep it the same when comparing charts. Use the print command to save any result as a PDF. The tools run in your browser and do not store what you enter. And when a result surprises you, read the Method page, which sets out how each value is computed, before drawing conclusions.