Calculate duration between two dates This service calculates the duration, counting the day count and the number of days, months and years between two dates.

Add to or subtract from a date This service enables you to add or subtract days, months and years to a date to calculate a past or future date.

List of Jewish Feast dates through 2017 

Hebrew Convertor  

Here is a lunar eclipse calculator that allows you to select a location and century from  0 AD to 3000 AD!!  Much more on lunar eclipses along with many links here.

Beast Calculator - type the name and get the number  Option 1  Option 2