Is there any information_schema view that can tell when an object privilege was granted?
The pg_namespace view doesn't have that.
select *from pg_namespacejoin lateral ( SELECT * from aclexplode(nspacl) as x) a on truejoin pg_user e on a.grantee = e.usesysidjoin pg_user r on a.grantor = r.usesysid where e.usename = '<<MY_USERNAME>>';