What a solar return is
Once a year the Sun comes back to the exact degree of the zodiac it occupied when you were born. The chart drawn for that moment is called a solar return, or a birthday chart. Modern astrologers read it as a picture of the themes of the year ahead, running from one birthday to the next. It is a tradition of reflection, not a forecast, and it works best as a prompt to ask what the year might be for.
Why the moment is not always your birthday
The Sun’s journey round the zodiac takes a little over 365 days. The calendar year is 365 days, with a leap day every fourth year, so the return moment drifts by about six hours from one year to the next and then jumps back after a leap year. That means your solar return can fall a day before or a day after your birthday, and its clock time is rarely the time you were born. This is why the tool needs your birth time: the Sun moves almost a degree a day, so a birth time that is an hour out moves the return by an hour.
How the tool finds it
Your local birth time is converted to universal time using the time zone in force at your birthplace on that date, daylight saving included. The tropical position of your natal Sun is read from Swiss Ephemeris data. The tool then starts from your birthday in the year you choose and nudges the clock until the Sun stands at exactly that position again. The return chart is drawn for that instant: the Ascendant, Midheaven and house cusps, the planets by sign and house, and the major aspects. The answer is shown in your local clock time for the chosen place, and in UTC.
Which place to use
Astrologers disagree about where a solar return should be cast. One school uses your birth place every year, on the view that the return belongs to your own chart. Another uses the place where you will be at the moment of the return, so the Ascendant and houses change if you travel. The tool defaults to your birth place and lets you add a second place so you can compare the two. Neither is proven better, and choosing is a matter of taste.
How to read the result
Start with the Ascendant sign, which sets the tone of the year, and then the house the Sun falls in, which is said to show where your attention gathers. Note the Moon’s sign and house for the mood, and any planet close to an angle (the Ascendant, Midheaven, and the two points opposite). Then compare the return chart with your birth chart, which you can find with the Sun, Moon and Rising calculator. Look for return planets that sit on your natal planets: that is where readers say the year touches your personality most directly.
What the tool does not do
It uses the tropical zodiac and the mean lunar node, and it does not show the sidereal (Vedic) form of the return, which is calculated differently. It makes no predictions. The descriptions are brief modern readings, and they describe tendencies in a style of reflection, not events. If a year ahead worries you for health, money or legal reasons, a solar return is the wrong tool and a qualified professional is the right person to talk to.
Frequently asked questions
↳ Do I need my exact birth time?
Yes. The Sun moves almost a degree a day, so the return moment shifts by about an hour for every hour of error in the birth time. The Ascendant, which changes sign about every two hours, depends on it even more.
↳ Why is my solar return on a different day from my birthday?
The return moment moves by about six hours a year against the calendar, with a jump back after a leap year. Depending on your birth time and the year, it can land on the day before or after your birthday.
↳ Should I use my birth place or where I am now?
Astrologers differ. Using the birth place keeps the chart tied to your own birth chart, while using your current place reflects where you spend the return moment. The tool shows either, so you can compare them.
↳ Is a solar return a prediction?
No. It is an interpretive tradition in which the sky at the Sun's return is read as a theme for the year. It is meant for reflection, and it cannot tell you what will happen.
↳ How accurate is the return time?
The Sun in the return chart matches your natal Sun to a small fraction of an arcsecond, which fixes the moment to within a few seconds. The result is only as accurate as the birth time you enter.