How to format bigint field into a date in Postgresql?

I have a table with a field of type bigint. This field store a timestamp. I want to date format the field like this :

to_char( bigint_field,'DD/MM/YYYY HH24:MI:SS')

I get the following error :

ERROR: multiple decimal points
État SQL :42601

Solution 1:

TO_CHAR(TO_TIMESTAMP(bigint_field / 1000), 'DD/MM/YYYY HH24:MI:SS')

Solution 2:

This is what worked for me

to_timestamp( bigint_field/1000)::date

Solution 3:

This depends on what the bigint value represents - offset of epoch time, or not.

select to_timestamp(20120822193532::text, 'YYYYMMDDHH24MISS')

returns

"2012-08-22 19:35:32+00"