Equinox and solstice dates with time
These equinox and solstice dates are calculated for any year from 1990 to 2100, accurate to about a minute. In 2026 spring begins on March 20 at 14:46 UTC, summer on June 21, autumn on September 23 and winter on December 21.
Example: Year 2,026 · Time zone: UTC (world time) · Hemisphere: Northern hemisphere → Start of spring: Start of spring 2026: Friday, 20 March 2026 at 14:46 UTC. Source: Wikipedia – Equinox and Solstice: definitions, dates, hemispheres. Updated: .
How it is calculated
Equinox and solstice dates – what they mean
Astronomically the seasons begin with the two equinoxes and the two solstices. In March and September the Sun stands directly above the equator at noon, and day and night are nearly equal. In June and December it reaches its northernmost or southernmost point: that is the solstice, which marks the start of summer or winter in the northern hemisphere.
Why the date moves
A year lasts about 365.2422 days, the calendar only 365 or 366. So the moments move within about a day, and depending on the time zone the date can differ. The March equinox usually falls on March 20 or 21, the June solstice on June 20 or 21.
Astronomical or meteorological
- Astronomical: the season starts at the moment of the equinox or solstice, as calculated above.
- Meteorological: weather services use whole months so that statistics stay comparable: spring from March 1, summer from June 1, autumn from September 1, winter from December 1.
The seasons differ in length because Earth’s orbit is an ellipse. In the northern hemisphere summer is longest at about 93.6 days and winter shortest at about 89 days.
Limits
The times use Jean Meeus’s method (mean values plus periodic terms) and are rounded to the minute. The accuracy is about one minute, and official almanacs can differ by that amount. Time zones follow the current daylight saving rules of each region.
Frequently asked questions
When do the seasons start in 2026?
Spring on March 20, summer on June 21, autumn on September 23 and winter on December 21 (in UTC). The exact times are shown above.
What is the difference between an equinox and a solstice?
At an equinox the Sun is directly above the equator, at a solstice above the Tropic of Cancer or Capricorn.
Why is the start of summer not always June 21?
Because the calendar year is not exactly as long as Earth’s orbit around the Sun. Leap years compensate, but the moment still moves by up to a day.
When does meteorological spring start?
Always on March 1. Weather services group the seasons into whole months.
How long do the seasons last?
Astronomically between about 89 and 94 days. The calculator shows the length for the chosen year.
Sources and legal basis
- Wikipedia – Equinox and Solstice: definitions, dates, hemispheres
- Jean Meeus, Astronomical Algorithms (2nd ed.), ch. 27 – formulas; comparison values: U.S. Naval Observatory, Earth’s Seasons
- NASA – Polynomial Expressions for Delta T (ΔT = TT − UT)
As of: · Editorial policy
Related tools
- Sun Position CalculatorSun position for any place and date: azimuth and altitude through the day as a chart, sunrise, solar noon, sunset and twilight – NOAA method, no app needed.
- Daylight saving time: when do the clocks change?Next daylight saving time change for your time zone with date, time and countdown, plus 2026 and 2027 dates for 40+ countries and which don’t change at all.
- Moon Phase Calendar 2026: Moon Phase Today and Full MoonMoon phase calendar 2026: today’s moon phase with illumination in percent, next full moon with time and countdown, monthly calendar, moon sign and moonrise.
- What week number is it today?Today’s week number (ISO 8601 and US count), the week of any date, the dates of any week and all week numbers of the year – with ICS export and print.
- What day of the year is it?Day of the year today or for any date: day number 1 to 366, days left, percent of the year passed, ISO ordinal date, Julian Date – and from number to date.
- World clock: current time around the worldWorld clock with seconds: current time in London, Tokyo, Dubai and 120+ cities, with time difference, DST, day or night and a meeting planner slider.
- Online TimerFree online countdown timer: enter any time or tap a 5, 10 or 15 minute preset, get an alarm when time is up, remaining time in the tab. No sign-up.
- How many days until Diwali?How many days until Diwali? Live countdown to Deepavali on Sunday, 8 November 2026, with the official date for 2027 and how many weeks are left.
- 10000 Days Old CalculatorWhen are you 10,000 days old, 1 billion seconds or 1,000 weeks? Enter your birth date and see every milestone with its date, weekday and how far away it is.