This plugin allows WordPress to easily show Hebrew dates instead of (or in addition to) the standard Gregorian dates. No theme changes are required.
Unzip the zip file, copy to /path/to/wordpress/wp-content/plugins/, activate, and configure! Note that sunset correction is disabled by default, since there's no meaningful default value for Latitude / Longitude
By default, the following APIs are intercepted: the_time() the_date() get_the_time() get_the_date() get_comment_time() get_comment_date()