Enter the code from the picture

Anniversary of Bulgarias staring to use the Gregorian Calendar

In 1916, at midnight on 31st of March, Bulgaria “jumps” into future – instead of having April 1st as the next day, Bulgarians had April 14th…. Yes, that was the day Bulgaria stepped from the Julian Calendar to the Gregorian one (also known as “new style calendar”)…

The Gregorian calendar is the calendar that is used nearly everywhere in the world. A modification of the Julian calendar, it was first proposed by the Calabrian doctor Aloysius Lilius, and was decreed by Pope Gregory XIII, for whom it was named, on 24 February 1582 via the papal bull Inter gravissimas. Its years are numbered using the anno Domini era, beginning with the traditionally accepted year of Jesus' birth.

More info - at Wikipedia