Answer:

In most countries around the world, students study at school for less than 10 months of a year, enjoying the remaining 2 months mostly as a long summer vacation. This, in my opinion, is a less efficient educational system for the students. Students who take very long summer vacations tend to forget what they have previously learned. This means that when school starts again, much time is wasted on refreshing the memories of the students. Ending this cycle with shorter summers results in a stronger, more productive school year.
When students have long summer vacations and only attend school nine or ten months out of the year, they tend to forget their lessons. This is especially true of older students, who are learning more difficult subjects such as high-level math and world history. The numerous summer weeks drift by and students just laze around and have fun, giving little thought to school. Bit by bit, the equations of algebra start to become hazy. The details of World War I become muddled. However, if summer break is just a month long and the students attend school the other eleven months of the year; their brains will retain far more information. They’re given just enough time to relax and then get right back to work. A two or three month summer break is dangerously long, which is unnecessary and damaging.
This loss of knowledge over long summers has even further negative effects on the part of the teachers. Teachers, at the start of the new school year, often notice that their students have forgotten their lessons from the previous year. To be able to move forward, the teachers have to repeat what they have taught previously. This could lead to an endless cycle of learning something, forgetting most of it, being reminded, over and over and over. Cutting short long vacations, giving students no opportunity to forget, is therefore very conducive towards more effective teaching.
Some people might argue that studying for 11 months of a year may be too stressful for students, so they need to break away from school for 2 or more months to relax, and to develop an interest in non-academic subjects such as music and painting. However, they don’t have to do so continuously over two or more months completely away from school.
There is always time after regular school hours like late afternoon periods, or during the weekends, when students can enjoy the fun of exploring something different.
That’s why I believe that a school year lasting eleven months would be a good idea. The very long summers where students forget information would be avoided. This would mean that the autumn lessons wouldn’t be just reminders of old, forgotten information. The school year would therefore be more productive. It would be heavily-focused on new information, getting to the students faster and sinking-in better.