In the US, schools have been out since the beginning of June. The start is usually late August.
There is no half term holiday in the US. Students go from late August to Columbus Day (one day) in October and then on to Thanksgiving weekend in late November (Thursday, Fri, and the weekend off) and then on to the Christmas/winter break which is two weeks. Then there are several long weekends in the late winter/early spring for Presidents Day, MLK day, etc. until Spring break, which is a week. Some schools take Good Friday off, maybe Holy Thursday too if RC or Lutheran.
The school year features longer stretches of work.
Teens in the US are able to commit to almost three months of work if they can get a summer job. It makes a huge difference to many.
Irish primary schools are required to be open 183 days a year and secondaries 167. They don't all follow the same calendar but secondary schools are usually out before the Junior Cert and Leaving Cert exams begin in early June.
Primary schools go until the third week of June more or less, and start up again in very late August/early September. I went to a private primary school and we were out at the end of May.
I remember as a child feeling immensely sorry for my English cousins slogging away during the fantastic summers of 1975 and 1976 while all the children from my road were out on our bikes and skates, enjoying the beach and having the time of our lives.