There is no year 0 (zero) in the Gregorian calendar. If you enter 0, this is interpreted as 1 BCE. If you enter a negative number like -1, this is interpreted to be 2 BCE. The year -99 is interpreted to be the year 100 BCE.
Also, please note: results for year 1752 C.E. and earlier are guaranteed to be inaccurate.
Hebcal does not take into account a correction of ten days that was introduced by Pope Gregory XIII known as the Gregorian Reformation. [1]
Ideas
There is no year 0 (zero) in the Gregorian calendar. If you enter 0, this is interpreted as 1 BCE. If you enter a negative number like -1, this is interpreted to be 2 BCE. The year -99 is interpreted to be the year 100 BCE.
Also, please note: results for year 1752 C.E. and earlier are guaranteed to be inaccurate.
Hebcal does not take into account a correction of ten days that was introduced by Pope Gregory XIII known as the Gregorian Reformation. [1]