To unambiguously specify the date, dual dating or Old Style (O.S.) and New Style (N.S.) are sometimes used with dates. Dual dating uses two consecutive years because of differences in the starting date of the year, or includes both the Julian and Gregorian dates. Old Style and New Style (N.S.) indicate either whether the start of the Julian year has been adjusted to start on 1 January (N.S.) even though documents written at the time use a different start of year (O.S.), or whether a date conforms to the Julian calendar (O.S.) rather than the Gregorian (N.S.). 

The Gregorian calendar was a reform of the Julian calendar instituted in 1582 by Pope Gregory XIII, after whom the calendar was named, by papal bull Inter gravissimas dated 24 February 1582. The motivation for the adjustment was to bring the date for the celebration of Easter to the time of year in which it was celebrated when it was introduced by the early Church. Although a recommendation of the First Council of Nicaea in 325 specified that all Christians should celebrate Easter on the same day, it took almost five centuries before virtually all Christians achieved that objective by adopting the rules of the Church of Alexandria (see Easter for the issues which arose).

Based on the article and the following list of answers, write a list of questions.

1. a reform of the Julian calenda
2. the pope
3. No
4. ope Gregory XIII
5. unknown
6. yes
7. 24 February 1582
8. no
9. bring the date for the celebration of Easter t
10. all Christians should celebrate Easter on the same day,

Numbered questions:
1. Which calendar is the Gregorian based on?
2. Who decided to do it?
3. Pope Francis?
4. Which?
5. Is that where the word Gregorian came from?
6. Did this happen in the sixteenth century?
7. What was the exact date it was first introduced?
8. Was it made because of Christmas?
9. What celebration was at the root of this new calendar?
10. What was their goal regarding Easter?