First off, when I mean time, I don't mean 24 hour time. I mean, days, months, year time. So, I have a few questions I would like to be answered.
Would different countries have different tracking of time? As in, would different countries think it was a different year?
Would having different methods of tracking time be conflicting?
When did people start recognizing the AD/BC time period? Thanks!
What you're referring to is the Gregorian Calendar; it's common today, although some countries do use other calendars either officially or for specific purposes (e.g. religion).
re question 1, there are some examples of other calendars in the FAQ Other dating systems
re question 3, there's some info on the development of the Gregorian Calendar in the FAQ How did the world agree on what year it is?