#1

SET time_zone = '+00:00';

#2

CREATE TABLE timestamp_n_datetime (
    id INT AUTO_INCREMENT PRIMARY KEY,
    ts TIMESTAMP,
    dt DATETIME
);

#3

INSERT INTO timestamp_n_datetime(ts,dt)
VALUES(NOW(),NOW());

#4

SELECT 
    ts, dt
FROM
    timestamp_n_datetime;

#5

SET time_zone = '+03:00';

SELECT 
    ts, dt
FROM
    timestamp_n_datetime;

#6

SET @dt =  NOW();

#7

SELECT @dt;

#8

SELECT DATE(@dt);

#9

CREATE TABLE test_dt (
    id INT AUTO_INCREMENT PRIMARY KEY,
    created_at DATETIME
);

INSERT INTO test_dt(created_at)
VALUES('2015-11-05 14:29:36');

#10

SELECT 
    *
FROM
    test_dt
WHERE
    created_at = '2015-11-05';

#11

SELECT 
    *
FROM
    test_dt
WHERE
    DATE(created_at) = '2015-11-05';

#12

SELECT TIME(@dt);

#13

SELECT 
    HOUR(@dt),
    MINUTE(@dt),
    SECOND(@dt),
    DAY(@dt),
    WEEK(@dt),
    MONTH(@dt),
    QUARTER(@dt),
    YEAR(@dt);

#14

SELECT DATE_FORMAT(@dt, '%H:%i:%s - %W %M %Y');

#15

SELECT @dt start, 
       DATE_ADD(@dt, INTERVAL 1 SECOND) '1 second later',
       DATE_ADD(@dt, INTERVAL 1 MINUTE) '1 minute later',
       DATE_ADD(@dt, INTERVAL 1 HOUR) '1 hour later',
       DATE_ADD(@dt, INTERVAL 1 DAY) '1 day later',
       DATE_ADD(@dt, INTERVAL 1 WEEK) '1 week later',
       DATE_ADD(@dt, INTERVAL 1 MONTH) '1 month later',
       DATE_ADD(@dt, INTERVAL 1 YEAR) '1 year later';

#16

SELECT @dt start, 
       DATE_SUB(@dt, INTERVAL 1 SECOND) '1 second before',
       DATE_SUB(@dt, INTERVAL 1 MINUTE) '1 minute before',
       DATE_SUB(@dt, INTERVAL 1 HOUR) '1 hour before',
       DATE_SUB(@dt, INTERVAL 1 DAY) '1 day before',
       DATE_SUB(@dt, INTERVAL 1 WEEK) '1 week before',
       DATE_SUB(@dt, INTERVAL 1 MONTH) '1 month before',
       DATE_SUB(@dt, INTERVAL 1 YEAR) '1 year before';