How I can display the thumeric value of the day of week into Greek?

Question

I have the following database:

create workers (
  id SERIAL PRIMARY KEY,
  name STRING
);

create works_zones (
  id SERIAL PRIMARY KEY,
  area_name String,
  work_from TIME WITHOUT TIMEZONE,
  work_until TIME WITHOUT TIMEZONE
) 

create table shifts (
  id SERIAL PRIMARY KEY,
  worker_id INT,
  day_of_week INT,
  work_zone INT,
  CONSTRAINT fk_worker FOREIGN KEY(worker_id) REFERENCES workers(id) ON DELETE CASCADE,
  CONSTRAINT fk_work_zone FOREIGN KEY(work_zone) REFERENCES works_zones(id) ON DELETE CASCADE
)

CREATE UNIQUE INDEX CONCURRENTLY unique_day_zone_worker ON shifts (worker_id,work_zone,"day_of_week");

And I try to list all worker shifts:

select 
 workers.name,
  works_zones.area_name,
  works_zones.work_from,
  works_zones.work_until,
  shifts.day_of_week
from 
  shifts
join
 workers on shifts.worker_id = workers.id
join
 works_zones on works_zones.id = shifts.work_zone

But how I can translate the day_of_week into human readable form and expecially localized into Greek? The values are ranging from 0 to 6 where ) is Sunday and 6 is Saturday.

Is there a way to do is without the use of Case...when .. end?