The vernal or spring equinox occurs on Monday, equalising the length of the day and night around the globe.
"The spring equinox is the moment when the sun's central point shifts from the southern night sky to the north," Yle meteorologist Joonas Koskela explains.
Night and day are equally long – about 12 hours – everywhere on the planet during the equinox. The day will now continue to lengthen in the northern hemisphere, and nights will become shorter.
"The closer you go to the poles, the more the time differences will fluctuate," Koskela notes.
For instance, in Utsjoki in northern Lapland the day is several minutes longer than in Helsinki.
"This is because the atmosphere refracts light. The sun can be seen for some moments even after it has actually sunk behind the horizon," says Koskela. "It will also appear to rise a moment before it actually does."
The length of the day began to lengthen just before Christmas, after the winter solstice. The day will now continue to get longer until Midsummer and the summer solstice.
Daylight savings time will come into effect on Sunday, March 26th -- at 3 am clocks move forward by one hour to 4 am. Most digital devices change on their own.