Counting time

History needs to place the facts in space and time, both coordinates are inseparables. 

Each civilization counts time through a calendar. We use the year (365 day, +1, every four years), lustrum (5 years), decade (10 years), century (100 years) and millennium (1000 years)

Our calendar usually starts by pointing the birth of Christ. To chronologically locate the events prior to the birth of Christ, we do so by counting backwards from his birth, the higher number, the older the historical event. 

When things happened before Christ was born, we add BC to the number, and for things that happened after Christ, we add AD (AD stands for Anno Dominici, which means “year of our Lord” in Latin).

If the date doesn’t say AD or BC, it is always AD.

Remember, in History there is not the year 0, so 1 is B.C and 1 A.D.

THE ROMAN NUMERALS

Centuries are written with Roman numerals.

The centuries go from the year 1 to 100-----1st century

                                               101 to 200-----2nd century

                                               201 to 300-----3rd century and so on

How to know to right century for a certain year?

-All the years from 1 to 100 (one-digit numbers and 100, correspond to the first century)

Examples:

-Three-digits numbers, you must take the hundreds and and add 1:

Examples:

   

-Four-digit numbers we must add 1 to the thousands and hundreds.

Examples:

    

EXPLANATORY VIDEO HERE