Solstice 2024 Timer. Thursday, june 20 is the official first day of northern astronomical summer for 2024 — summer solstice — which is the longest day of the year for this half of the planet. That's the first sunday in november, and marks the return to standard time.
That will put us back into standard time and end daylight saving time (dst). The vernal equinox marks the beginning of astronomical spring, while.