-- Convenience Functions
CREATE OR REPLACE FUNCTION to_epoch(IN timestamptz, OUT epoch bigint) AS
  $$ SELECT extract(epoch from $1) $$ LANGUAGE SQL;
CREATE OR REPLACE FUNCTION ts_at_tod(IN timestamptz, IN time, OUT timestamptz) AS
  $$ SELECT date_trunc('day', $1) + $2 $$ LANGUAGE SQL;

-- Get list of target time between start and end
CREATE OR REPLACE FUNCTION times_between(IN range_start timestamptz, IN range_end timestamptz, IN t time)
  RETURNS setof timestamptz AS $$
    SELECT * FROM
      generate_series(
        ts_at_tod($1,$3),
        ts_at_tod($2,$3),
        '1 day'
        ) g
      WHERE g.g BETWEEN $1 AND $2;
  $$ LANGUAGE SQL;