It is very easy task as it requires only the use of ncal command.
Get the date of Easter for the current year:
$ ncal -e March 31 2013 |
Get the date of Easter for the next year:
ncal -e $(date --date "next year" +"%Y") April 20 2014 |
Get the date of Easter for the 2015 year:
ncal -e 2015 April 5 2015 |