Sie verwenden to_timestamp -Funktion und wandeln Sie dann den Zeitstempel in date um
select to_timestamp(epoch_column)::date;
Weitere Einzelheiten:
/* Current time */
select now(); -- returns timestamp
/* Epoch from current time;
Epoch is number of seconds since 1970-01-01 00:00:00+00 */
select extract(epoch from now());
/* Get back time from epoch */
-- Option 1 - use to_timestamp function
select to_timestamp( extract(epoch from now()));
-- Option 2 - add seconds to 'epoch'
select timestamp with time zone 'epoch'
+ extract(epoch from now()) * interval '1 second';
/* Cast timestamp to date */
-- Based on Option 1
select to_timestamp(extract(epoch from now()))::date;
-- Based on Option 2
select (timestamp with time zone 'epoch'
+ extract(epoch from now()) * interval '1 second')::date;
In Ihrem Fall:
select to_timestamp(epoch_ms / 1000)::date;
PostgreSQL-Dokumentation
