/**
 * Creates two functions which returns unix timestamp for the a given timestamp
 * or a given timestamp with time zone.
 *
 * @author: "Stefanie Janine Stölting"<stefanie@proopensource.eu>
 * @license: PostgreSQL https://opensource.org/licenses/postgresql
 */

CREATE OR REPLACE FUNCTION to_unix_timestamp(ts timestamp) RETURNS bigint AS $$
	SELECT EXTRACT (EPOCH FROM ts)::bigint;
$$ LANGUAGE SQL STRICT IMMUTABLE
;
COMMENT ON FUNCTION to_unix_timestamp(ts timestamp) IS 'Returns an unix timestamp for the given timestamp';

CREATE OR REPLACE FUNCTION to_unix_timestamp(ts timestamp with time zone) RETURNS bigint AS $$
	SELECT EXTRACT (EPOCH FROM ts)::bigint;
$$ LANGUAGE SQL STRICT IMMUTABLE
;
COMMENT ON FUNCTION to_unix_timestamp(ts timestamp with time zone) IS 'Returns an unix timestamp for the given timestamp with time zone';