It makes sense to start with the year zero when you want to do any calculations that involve dates that where before and after year one.
If an empire was founded in 50 BC and dissolved in 50 CE to calculate its age when it was dissolved you have to acknowledge that there is no year zero so instead of just calculating 50 - (-50) = 100 you have to substract one which is counter intuitive. Because it went from year 1 BC straight to 1 CE.
The length of time an empire existed isn’t really important in the study of history. You need to describe the contextual existence of the empire within history, and you do that by specifying the start and end dates (in whatever calendar system you want to use). Using your example, if you say that empire existed for 101 years, why is that significant? It’s not. But if I say that empire existed in the middle east during the time of Christ and Roman occupation of Palestine, THAT provides the important historical context for why that empire was significant, and what kind of importance it may have had.
It makes sense to start with the year zero when you want to do any calculations that involve dates that where before and after year one. If an empire was founded in 50 BC and dissolved in 50 CE to calculate its age when it was dissolved you have to acknowledge that there is no year zero so instead of just calculating 50 - (-50) = 100 you have to substract one which is counter intuitive. Because it went from year 1 BC straight to 1 CE.
The length of time an empire existed isn’t really important in the study of history. You need to describe the contextual existence of the empire within history, and you do that by specifying the start and end dates (in whatever calendar system you want to use). Using your example, if you say that empire existed for 101 years, why is that significant? It’s not. But if I say that empire existed in the middle east during the time of Christ and Roman occupation of Palestine, THAT provides the important historical context for why that empire was significant, and what kind of importance it may have had.