Days Until Summer Solstice

When is Summer Solstice?

The June solstice, around June 21, is the longest day of the year in the Northern Hemisphere and the official start of astronomical summer. The exact moment varies by a day either side depending on the year.

This countdown uses June 21 as the conventional solstice date for a quick days-to-go estimate.

Summer Solstice dates, 2026–2035

The next 10 occurrences, with the weekday each falls on and the Unix timestamp of midnight UTC at the start of the day.

The story behind Solstice

The word solstice comes from the Latin sol, sun, and sistere, to stand still, because for a few days around it the Sun's noon height stops changing before reversing. At the June solstice the Sun is directly overhead at the Tropic of Cancer, everywhere north of the Arctic Circle has 24 hours of daylight, and the Northern Hemisphere has its longest day while the Southern Hemisphere has its shortest. The extra daylight has nothing to do with distance: Earth is actually near aphelion, its farthest point from the Sun, in early July. The astronomical instant drifts around the calendar because a year is not a whole number of days. It moves about six hours later each year and jumps back a day at each leap year, so within the current cycle it falls on June 20 in leap years and June 21 in the others, and it will not fall on June 22 again in this century. Monuments from Stonehenge to the Chichén Itzá pyramid are aligned to it, and midsummer festivals cluster around it: Sweden's Midsommar, Finland's Juhannus and the bonfires of St. John's Eve on June 23 all descend from older solstice celebrations.

How this countdown is calculated

The astronomical solstice shifts between June 20 and June 21 depending on the year, so for a simple, predictable countdown this page uses June 21 as the conventional date and targets midnight at the start of the next June 21 in your local time zone. In a leap year the true solstice may arrive up to a day earlier than the countdown suggests.

The big number at the top of this page is computed live in your browser the moment the page loads and ticks down every second — there is no stale, pre-baked figure here. It measures the gap between your current local time and the next June 21, then breaks it into days, hours, minutes, and seconds. Because the math runs on your own device, the result is always correct for your time zone and is never cached out of date.

The Unix timestamp of Summer Solstice

Beyond the human-friendly countdown, this page also shows the Unix timestamp of the target date — the number of seconds since January 1, 1970 UTC. That single integer is what databases, schedulers, and APIs actually store. If you are building a feature that fires on Summer Solstice — a banner, an email, a cron job — the timestamp shown above is the value to compare against. You can also drop the date straight into the Epoch Converter to inspect it in every format, or into the Date Duration Calculator to measure the span from any other date.

Ways people use a Solstice countdown

• Planning — knowing the exact number of days left helps with shopping, travel, and booking before deadlines pass.
• Sharing — send the live countdown link to friends, family, or a team channel so everyone sees the same ticking clock.
• Engineering — use the Unix timestamp above to schedule jobs or gate features around the date.
• Curiosity — sometimes you just want to know "how many days until Solstice?" and get a precise answer rather than a rough guess.

Want a different date?

This page is part of a small reference of common countdowns and notable timestamps. Browse the full timestamp and countdown hub to find New Year, Christmas, Halloween, the Y2038 deadline, and more — or build a countdown to any moment of your choosing with the Countdown Timer.

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