Russia has celebrated May Day since 1917, but it was only proclaimed an international holiday in 1918. In 1928, the Labor Code was amended, and May 2 was declared an additional non-working International Day holiday. Although the holiday had its roots in ancient European spring celebrations, by 1904, the international labor movement had dedicated the day to the drive to establish an 8-hour work day. Each year, hundreds of thousands of Soviet citizens celebrated the law that established the shorter shift; previously, workers had toiled for as many as 10-16 hours every day.