从字符串的postgresql-epoch转换

Question

I need help in converting string which is in the format of YYYYMMdd string to AMERICAN CST, but currently by default it's converting to GMT. not sure how to fix this, any suggestions on this.

select case when trim(end_dt)='00010101' then 0
            else extract(epoch from to_date(end_dt,'YYYYMMDD'))*1000
       end as end_date
from tbl;