What is the longest daylight day of the year in the US?

It's commonly referred to as "Mid-Summers Night Eve" or "The Summer Solstice" and it usually happens on or around the 21st of June. This is the longest day and the shortest night of the year. From this day on the days get shorter and the nights longer until the Winter Solstice which is the other way around; the shortest day and the longest night of the year after which the days start getting longer and nights shorter.