Druuid PostgreSQL support: https://github.com/recurly/druuid

druuid.sql

CREATE OR REPLACE FUNCTION public.epoch_offset() RETURNS bigint AS $$
	BEGIN
		RETURN 135702720000; -- 2013-01-01 00:00:00
	END;
$$ LANGUAGE plpgsql;

CREATE OR REPLACE FUNCTION public.druuid(epoch bigint default NULL) RETURNS bigint AS $$
	DECLARE
		result bigint;
	BEGIN
		epoch  := COALESCE(epoch, (SELECT FLOOR(EXTRACT(EPOCH FROM clock_timestamp()) * 100)));
		result := (epoch - epoch_offset()) << 23;
		result := result | (FLOOR(RANDOM() * 1e16)::bigint % 8388608);
		
		RETURN result;
	END;
$$ LANGUAGE plpgsql;

CREATE OR REPLACE FUNCTION public.druuid_epoch(druuid bigint) RETURNS bigint AS $$
	BEGIN
		RETURN (druuid >> 23) + epoch_offset();
	END;
$$ LANGUAGE plpgsql;

CREATE OR REPLACE FUNCTION public.druuid_time(druuid bigint) RETURNS timestamp AS $$
	DECLARE
		ms bigint := druuid_epoch(druuid);
	BEGIN
		RETURN (SELECT TIMESTAMP 'epoch' + (ms / 1e2) * INTERVAL '1 second');
	END;
$$ LANGUAGE plpgsql;

SELECT epoch_offset();
-- 135702720000

ALTER TABLE users ALTER COLUMN id SET DEFAULT druuid()

You can also pass an epoch in milliseconds as an argument.

SELECT druuid(136762687675)
-- 8891653325149927

And retrieve the epoch/time from the id

SELECT druuid_epoch(8891653325149927)
-- 136762687675

SELECT druuid_time(8891653325149927)
-- 2013-05-04 00:21:16.75