How to get current or custom time in different time zone in Oracle DB ?

To get current time in another time zone use the following :

SQL> select systimestamp at time zone 'ZONE_NAME' from dual ;

ZONE_NAME can be gotten from v$timezone_names view.

To get custom time of different timezone in local time zone do the following :

SQL> select to_char ( to_timestamp_tz ('2021-07-22 02:00 pm us/eastern','yyyy-mm-dd hh:mi pm tzr') at time zone 'europe/minsk', 'dd.mm.yyyy hh24:mi:ss') from dual

Thus, here we can see the local time (time in Minsk in my case) when there is 02:00 PM 22.07.2021 at US Eastern time. 

Here also the other samples :

select to_char (from_tz (to_timestamp ('2021-09-08 07:00am','yyyy-mm-dd hh:miam')  ,'America/Los_Angeles') at time zone 'Europe/Minsk', 'dd.mm.yyyy hh24:mi:ss') as local_time
from dual
/

select to_char (from_tz (cast (to_date ('2021-09-08 07:00am','yyyy-mm-dd hh:miam') as timestamp), 'america/los_angeles') at time zone 'europe/minsk', 'dd.mm.yyyy hh24:mi:ss') as local_time
from dual
/

Good Luck !