Re: BUG #15445: Difference between two dates is not an integer

Hello

Works for me in pg 10.5, 11.0, and 9.6

Try this query:
SELECT n.nspname as "Schema",
  o.oprname AS "Name",
  CASE WHEN o.oprkind='l' THEN NULL ELSE pg_catalog.format_type(o.oprleft, NULL) END AS "Left arg type",
  CASE WHEN o.oprkind='r' THEN NULL ELSE pg_catalog.format_type(o.oprright, NULL) END AS "Right arg type",
  pg_catalog.format_type(o.oprresult, NULL) AS "Result type",
  coalesce(pg_catalog.obj_description(o.oid, 'pg_operator'),
           pg_catalog.obj_description(o.oprcode, 'pg_proc')) AS "Description"
FROM pg_catalog.pg_operator o
     LEFT JOIN pg_catalog.pg_namespace n ON n.oid = o.oprnamespace
WHERE o.oprname OPERATOR(pg_catalog.=) '-'
  AND o.oprleft OPERATOR(pg_catalog.=) (select oid from pg_type where typname OPERATOR(pg_catalog.=) 'date')
  AND o.oprleft OPERATOR(pg_catalog.=) o.oprright
  AND pg_catalog.pg_operator_is_visible(o.oid)
ORDER BY 1, 2, 3, 4;

Maybe you have custom operators?

regards, Sergei