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 for the following month. The item for January is "0"; for February or March, "3"; for December, "12". Day-item: The total, thus reached, must be corrected, by deducting "1" (first adding 7, if the total be "0"), if the date be January or February in a leap year, remembering that every year, divisible by 4, is a Leap Year, excepting only the century-years, in `New Style', when the number of centuries is not so divisible (e.g. 1800). The final result gives the day of the week, "0" meaning Sunday, "1" Monday, and so on. Examples: 17, divided by 4, leaves