Despite the fact that the population had to use the Muslim calendar in its dealings with the central and local authorities, the I Bulgarians continued to use the Christian I calendar in their everyday life and public relations. In certain contexts, its use developed into a distinctive feature of ethnic-religious belonging. Also, almost until the I Liberation, the rhythm of time for the I Bulgarian was dictated by his work activities. Tradition also controlled the holiday calendar and the ways of spending the leisure time. The only relatively lucid change was related to the appearance of the clock, which occupied its place in the life of Bulgarians after the 17th century. In the second and third quarters of the 19th century, the achievements of modem European civilization integrated the Bulgarians into the bourgeois epoch and urged them to rethink and enrich not only their value system, but also the notions of time in the physical, philosophical and historical sense. The signs of this change can be found in different domains – the ever-diminishing use of the Julian calendar, the enhanced interest of educated Bulgarians in studying the calendar of their ancient forefathers, the philosophical insight of the Apostle of Freedom, Vasil Levski, “Time is in us and we are in time, it changes us and we change it..
On 1 April 1916, the Bulgarian calendar went 13 days ahead in time and the date became 14 April because of the shift from the Julian to the Gregorian calendar. The reason for the change was political. In the years of the First World War, Bulgaria was an ally of Germany and Austria-Hungary, which used the Gregorian calendar. The variance in the dates caused misunderstandings, which had to be overcome. But the secular authorities did not impinge on religious holidays, which were determined solely by the Church. The different denominations preserved their calendars in acts and documents of religious nature.
Time is measured in years and anniversaries are measured by time. “Golden/silver” jubilees became popular in the Kingdom of Bulgaria (1878-1946) and the People’s Republic of Bulgaria (1946-1991) not only in relation to people or historical events, but also as a sign of empowerment. For example, Tsar Ferdinand (1887-1918) celebrated his enthronement every five years. Todor Zhivkov, Secretary General of the Bulgarian Communist Party (1954-1989), also marked the April Plenum of 1956 at which he assumed power, by staging party congresses every five years. Such “calendar affinity” is a sign of the rulers who identify a historical epoch with themselves.