Which calendar, introduced in 46 BC, had a regular year of 365 days divided into 12 months, and a leap day added to February every four years?
It could be the Gregorian calendar
What name is given to a special day or happening, used variously over centuries to mark important days in a calendar, to mark capitals or rubrics in religious texts, or to wear particular clothing?
Which planet has a year of 687 days, a day of 24 hours 37 minutes, a diameter twice that of the moon and a mass one tenth of the earth?
US President Bush sent 2,000 troops into which country to conduct regular military exercises and, after a US serviceman was shot by local forces in December 1989, ordered an additional 24,000 troops in to take control?