Enable learners to calculate historical time using CE/BCE, centuries, and millenniums, recognizing the absence of 'year zero'.
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Highlight the mathematical trick of calculating years across BCE and CE.
In the Gregorian calendar, there is no 'year zero'; the year 1 CE immediately follows 1 BCE. To calculate the total number of years between a BCE date and a CE date, you must add the two years together and subtract 1.
Example: Finding how many years ago Buddha was born (approx. 560 BCE) relative to the year 2024 CE.
Introduction to the Gregorian calendar, CE, and BCE.
The calendar most commonly used worldwide today is the Gregorian calendar. In this system, the conventional year for the birth of Jesus Christ is used as the central dividing point for counting historical years.
Visual timeline showing BCE counting down and CE counting up.
The birth of Jesus is the conventional dividing point for historical dates.
Defining longer spans of time and mentioning alternative calendars.
Along with years and decades, historians use the term Century to describe any period of 100 years. Centuries are counted every 100 years starting from 1 CE.
For instance, we are currently in the 21st century CE, which runs from 2001 to 2100.
Practice calculating centuries and time spans.
The Rani of Jhansi was born in the year 1828 CE. To which century does her birth year belong?