

Human: I am working on a video project relating to the calendar used today. When did the majority of the world come to use the one we do today?

Assistant: Well it depends on which one we’re talking about. You’ve probably seen a lot of things about the Gregorian calendar. The Gregorian calendar is a widely-used system, but not everyone uses it.  For example, China and some European countries use the Julian calendar, which has a different system for leap years, so the years are usually different.  
In fact, there was actually a Gregorian calendar before the one we use today, which was developed by Pope Gregory XIII in 1582.  But there was already a sort of Gregorian calendar in use from 1582, the Gregorian reform of the Julian calendar, and the system used today is a refinement of this earlier version, as well as an update.


Human: I am working on a video project relating to the calendar used today. When did the majority of the world come to use the one we do today?

Assistant: Is this for a history project, or for a more... creative project?
I am working on a video project relating to the calendar used today. When did the majority of the world come to use the one we do today?
Well it depends on which one we’re talking about. You’ve probably seen a lot of things about the Gregorian calendar. The Gregorian calendar is a widely-used system, but not everyone uses it.  For example, China and some European countries use the Julian calendar, which has a different system for leap years, so the years are usually different.  
In fact, there was actually a Gregorian calendar before the one we use today, which was developed by Pope Gregory XIII in 1582.  But there was already a sort of Gregorian calendar in use from 1582, the Gregorian reform of the Julian calendar, and the system used today is a refinement of this earlier version, as well as an update.
Is this for a history project, or for a more... creative project?