The optimal age for starting school is discussed in other countries.  For example ( i have read this on https://www.amblesideprimary.com/) in neighboring France, children will soon begin to go to kindergarten from the age of three.  This is provided for by the reform program of President Emmanuel Macron, which will enter into force in September 2019.

As a rule, children begin to study at the age of four to five years.  If the child has reached the desired age by a certain date (it can range from the beginning of April to the end of July, again, in each of the 26 cantons in its own way), he can go to the garden at the beginning of the next school year, which  Switzerland traditionally starts in late summer. More cool information look at https://pro-papers.com/report-writing-service