In Japan, most people have their summer holidays in the middle of August. It’s starting today for most Japanese. I think a true holiday is when everyone is off at same time. During the holidays, we don’t like receiving business emails and phon calls.
However, the people in the entertainment industry are busy during the summer holidays. There are many concerts, live events, and more. They can’t enjoy their summer holidays during the actual summer. They often take time off after the summer, like in autumn.
If you’re not in the entertainment industry, you should take your summer holidays during the actual summer.