Calendars are very helpful to establish chronology in many different contexts.
As part of these explanation, it is necessary to remember that time has not been measured the same in different countries or civilizations, so, historians must understand this first and then try to interpret how it worked and how it affected some moments of history.
The First Amendment (I amendment) provides that Congress make no law respecting an establishment of religion or prohibiting its free exercise. It protects freedom of speech, the press, assembly, and the right to petition the Government for a redress of grievances. So, no.
The five-year plans do not certainly justify the tremendous cost borne by the soviet people. This is because the plan only brought glory to Stalin but did not improve the welfare of the people as is reflected in the economic gap between the Soviets and other western democracies