Syntax
------

NOW([precision])
CURRENT_TIMESTAMP
CURRENT_TIMESTAMP([precision])
LOCALTIME, LOCALTIME([precision])
LOCALTIMESTAMP
LOCALTIMESTAMP([precision])

Description
-----------

Returns the current date and time as a value in 'YYYY-MM-DD HH:MM:SS' or
YYYYMMDDHHMMSS.uuuuuu format, depending on whether the function is used in a
string or numeric context. The value is expressed in the current time zone.

The optional precision determines the microsecond precision. See Microseconds
in MariaDB.

NOW() (or its synonyms) can be used as the default value for TIMESTAMP columns
as well as, since MariaDB 10.0.1, DATETIME columns. Before MariaDB 10.0.1, it
was only possible for a single TIMESTAMP column per table to contain the
CURRENT_TIMESTAMP as its default.

When displayed in the INFORMATION_SCHEMA.COLUMNS table, a default CURRENT
TIMESTAMP is displayed as CURRENT_TIMESTAMP up until MariaDB 10.2.2, and as
current_timestamp() from MariaDB 10.2.3, due to to MariaDB 10.2 accepting
expressions in the DEFAULT clause.

Changing the timestamp system variable with a SET timestamp statement affects
the value returned by NOW(), but not by SYSDATE().

Examples
--------

SELECT NOW();
+---------------------+
| NOW()               |
+---------------------+
| 2010-03-27 13:13:25 |
+---------------------+

SELECT NOW() + 0;
+-----------------------+
| NOW() + 0             |
+-----------------------+
| 20100327131329.000000 |
+-----------------------+

With precision:

SELECT CURRENT_TIMESTAMP(2);
+------------------------+
| CURRENT_TIMESTAMP(2)   |
+------------------------+
| 2018-07-10 09:47:26.24 |
+------------------------+

Used as a default TIMESTAMP:

CREATE TABLE t (createdTS TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP);

From MariaDB 10.2.2:

SELECT * FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_SCHEMA='test'
 AND COLUMN_NAME LIKE '%ts%'\G
*************************** 1. row ***************************
     TABLE_CATALOG: def
      TABLE_SCHEMA: test
       TABLE_NAME: t
      COLUMN_NAME: ts
    ORDINAL_POSITION: 1
     COLUMN_DEFAULT: current_timestamp()
...

<= MariaDB 10.2.1

SELECT * FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_SCHEMA='test'
 AND COLUMN_NAME LIKE '%ts%'\G
*************************** 1. row ***************************
     TABLE_CATALOG: def
      TABLE_SCHEMA: test
       TABLE_NAME: t
      COLUMN_NAME: createdTS
    ORDINAL_POSITION: 1
     COLUMN_DEFAULT: CURRENT_TIMESTAMP
...

URL: https://mariadb.com/kb/en/now/