Postgres 11

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create table test (ts1 timestamp without time zone, ts2 timestamp with time zone)

CREATE TABLE


insert into test (ts1, ts2) 
VALUES ('2019-01-07 21:43:00', '2019-01-07 20:43:37+01'), 
       ('2019-01-07 21:43:00', '2019-01-07 20:43:37-01')

INSERT 0 2


select *, 
       to_char(ts1, 'YYYYMMDDHH24MI') str_ts1, 
       to_char(ts2, 'YYYYMMDDHH24MI') str_ts2, 
       to_char(ts1, 'YYYYMMDDHH24MI') = to_char(ts2, 'YYYYMMDDHH24MI') compare 
from test


ts1
ts2
str_ts1
str_ts2
compare


2019-01-07 21:43:00
2019-01-07 19:43:37+00
201901072143
201901071943
f

2019-01-07 21:43:00
2019-01-07 21:43:37+00
201901072143
201901072143
t



SELECT 2

ts1	ts2	str_ts1	str_ts2	compare
2019-01-07 21:43:00	2019-01-07 19:43:37+00	201901072143	201901071943	f
2019-01-07 21:43:00	2019-01-07 21:43:37+00	201901072143	201901072143	t