They are ordered by the government for all public workers and recommended for private comanies. It's a very common practice to make a better use for holidays. So three Saturdays in a row will be working days. But Monday April, 30 will be a holiday instead and russians will get three days out of work Sunday-Monday-Tuesday instead of Saturday-Sunday-Tuesday.Next week will be the same. Saturday, May, 5 and Saturday, May, 12, are working days for Monday and Tuesday, May 7 and 8. And four days from May 6 to May 9 will be holidays.