Postgres: How to return timestamp with local timezone

get-local-timezone.sql

select
  id,
  "utcStartTime",
  "utcOffset",
  "localStartTime" || "utcOffset" as "startTime"
from (
  select 
    id,
    "startTime" as "utcStartTime", 
    ("startTime" at time zone 'UTC' at time zone "timezoneOffset")::timestamp as "localStartTime",
    "timezoneOffset" as "utcOffset"
  from "myTable" 
  where id in (
	'cb354b18-2c07-49a8-85b6-e05b9a9e1993', 
	'00000004-b14f-4012-b115-43a49db5b76f',
	'ffffffd8-3c29-43d0-b1d9-631760ed055d'
  )
) as tmp