Not like in Europe, school year in Japan starts in April. Pupils and students start their new school life from April and end in March next year.
However, a pupil born on 01 April 2012 will not join the same grade with a different pupil born on 02 April 2012 or 31 March 2013. The pupil or student born on 01 April 2012 has to attend the school with classmates who are born between 02 April 2011 and 31 March 2012. Therefore there are many parents who register their children's birthdays as 02 April instead of 01 April.
01 April is a day for high school and university graduates to join the new companies. Therefore, moving season is also in spring mostly in March which means stores which sell home appliances such as fridge, washing machine or TV are mostly sold during this season.