Copyright: DTime v2.0 (C) PJ Naughter 1996


DTime Calendar Configuration

This control panel applet  allows a number of values used by C++ programs which use the DTime package to be modified in a controlled way. The values are stored per user and can be inspected in the system registry under the HKEY_CURRENT_USER\Control Panel\DTime key.

The applet allows the following parameters to be set:

•	The date when the JULIAN calendar ceased in your country.

•	The date when the GREGORIAN calendar was introduced in your country.


Julian Calendar

The Julian Calendar was the calendar system commonly in use throughout the Western world prior to the middle ages. It was established in the Roman Empire by Julius Caesar in the year -45 and reached its final form about the year +8. The main features of the Julian calendar were that a year consisted of 365 days except every 4 years where an extra day is added, namely the 29 of February. This gives an average of 365.25 days which is quite close to the current value for the length of a solar year.


Gregorian Calendar

The Gregorian Calendar was a reform of the Julian Calendar to more accurately reflect the true length of a year with respect to our civil time-keeping. By the time of the 1600’s the seasons were out of sync with the calendar by almost 2 weeks. As a result the day following 1582 October 4 (Julian Calendar) is 1582 October 15 (Gregorian Calendar). In this system every fourth year is still leap with the following exception. If the year ends with two zeros, then the year is leap if it is divisible by 400 not 4. This means that an extra 3 days are lost every 400 years. This gives an average of 365.2425 days which is very close to the current value of a solar year. This new calendar system was not at once officially adopted by all countries. e.g. In Great Britain the change was made as late as 1752, and in Turkey not before 1927.