"Sumardagurinn fyrsti," which translates to "the first day of summer," is an annual public holiday in Iceland. In Iceland, Sumardagurinn fyrsti marks the beginning of the summer season, even though the weather may not always reflect this. It falls on the first Thursday after April 18th each year. The holiday is celebrated with various events and activities that signify the arrival of warmer weather and longer daylight hours, including outdoor festivals, sporting events, and gatherings with family and friends.