Solar Return Calculator

What is a solar return?

In astrology, the moment each year when the Sun returns to the exact zodiac longitude it held at your birth. Because a tropical year is about 365.2422 days, that moment drifts around your calendar birthday and is usually on the birthday itself or a day either side. A chart cast for that moment is called a solar return chart and is read for the year ahead. That reading is tradition, not a tested method.

How does the calculator find the date?

It starts from your birthday in the chosen year, then compares n tropical years of 365.2422 days with the number of calendar days that have really passed since your birth date, where n is the number of years elapsed. The difference is 0.2422 days per year minus any leap days in between. The date is moved back one day if that difference falls below −0.5, forward one day if it is 0.5 or more, and otherwise left alone.

What does it assume about my birth time?

That you were born at midday UTC. The tool asks only for the birth date, not the time or the place. A real solar return depends on the exact minute and longitude of birth, so someone born late in the evening or early in the morning can have a return one day away from the one shown.

How are 29 February birthdays handled?

In non-leap years the anniversary is taken as 28 February and the same drift rule is applied, which can move it to 1 March. For a 29 February 2000 birth the tool gives 28 February 2026 and 1 March 2027, then 29 February in the leap year 2028. These are the dates the rule produces, not a legal or calendar convention.

Does the tool calculate the solar return chart itself?

No. It returns calendar dates only. It does not find the exact minute of the return, the Ascendant for the place where you are that year, or the planets in the return chart. Those need an ephemeris and your birth time.

What do “Days until / since” and “Age at next solar return” mean?

The first compares the chosen year’s date with today’s date and says how many days away or ago it is, or “Today!”. The age is the next year minus your birth year, so a 1990 birth with the year set to 2026 shows 37. Neither value checks whether your birthday has already passed this year.

What range of years is accepted?

The year field is held between 1900 and 2100. A year of 0, which is also what a cleared box becomes, or an invalid year becomes 2025. If the birth date field is empty the tool uses 15 June 1990.

Is any of this scientifically validated?

The length of the tropical year is an astronomical measurement, but astrology is a traditional, belief-based practice whose claims have not been scientifically validated. The tool predicts nothing; the line it prints about the meaning of a solar return is a traditional description.