Some postgres funcs and tricks

Postgres

postgres=# SELECT now(), current_date, current_time,  current_time - '1m'::interval, now() - '1m'::interval;
              now              |    date    |       timetz       |      ?column?      |           ?column?
-------------------------------+------------+--------------------+--------------------+-------------------------------
 2018-10-08 13:20:55.115306+00 | 2018-10-08 | 13:20:55.115306+00 | 13:19:55.115306+00 | 2018-10-08 13:19:55.115306+00

postgres=# select extract(dow from  current_date);
 date_part
-----------
         1

postgres=# select to_char(current_date, 'day');
  to_char
-----------
 wednesday

postgres=# select extract(dow from  current_date);
 date_part
-----------
         2
         
postgres=# select now() AT TIME ZONE 'Europe/Kiev';
          timezone
----------------------------
 2018-10-09 12:10:24.948787