First day of school is September 11, or the first Monday following if September 11 is a Saturday or Sunday. According to a 2010 decree of Polish Minister of Public Education, the first day of school for regular compulsory education schools in Poland is on September 1 or the first following Monday if September 1 falls on Friday, Saturday or Sunday. The last day is the last Friday after 18th of June. Previously, according to a similar 2002 decree, the above exception was only for Saturday and Sunday, and the last day was the first Friday after June 18. Schools in Russia (and formerly
Determination of the day of the week Determination of the day of the week The determination of the day of the week for any date may be performed with a variety of algorithms. In addition, perpetual calendars require no calculation by the user, and are essentially lookup tables. A typical application is to calculate the day of the week on which someone was born or a specific event occurred. In numerical calculation, the days of the week are represented as weekday numbers. If Monday is the first day of the week, the days may be coded 1 to 7, for Monday through Sunday, as is practiced in