The summer solstice begins just before 10pm today, a day earlier than usual.
The longest day and shortest night of the year normally falls on 21 June.
David Moore, editor of Astronomy Ireland magazine, said this year’s solstice is the earliest it has happened since 1796.
“This one is a bit of a record because it is the earliest that it has happened, 20 June 9.50pm tonight, since 1796.”
Speaking on RTÉ’s News at One, Mr Moore explained why it has come early this year.
“The earth is going around the sun every year, and the year isn’t an exact number of days. It is 365 and a quarter days long, roughly speaking. So, we have to reset our calendar every four years with a leap day at the end of February.”
He said this resets the exact moment we reach the solstice, adding that this is the start of summer in the Northern Hemisphere.
“Because what is happening is the earth’s axis is tilted directly toward the sun, the closest it can get pointing toward the sun.”
