2025 Summer Calendar Dates 2025. Discover the dates of uk bank holidays and other days of special interest in 2025. Short courses have separate deadlines.

Summer 2025 starts on friday, june 20th in the northern hemisphere, with the first day of summer being the longest daylight day of the year with the earth’s axis having reached its furthest tilt and begins to change directiion back. Dates and deadlines listed on this page include full semester and 7.5 week sessions only.