This is the 12633rd most frequent Swedish word.
sommarlovets
"Of the summer break" or "the summer break's" (possessive form).
In this sentence, 'sommarlovets' represents the possessive form referring to 'the summer vacation's', indicating ownership of 'the first week'.
Under sommarlovets första vecka åkte vi till stranden.
During the first week of the summer vacation, we went to the beach.
Here, 'sommarlovets' describes the freedom and sunny days as characteristics belonging to 'the summer vacation', denoting possession or association.
Barnen njöt av sommarlovets frihet och soliga dagar.
The children enjoyed the freedom and sunny days of the summer vacation.
In this context, 'sommarlovets' is used possessively to relate the highlights directly to 'the summer vacation'.