now(), date(), day(), time() functions in mysql code example

Example 1: mysql get time from datetime

SELECT 
date_format(datecol, '%H:%i:%s') as 'time' FROM table;
-- eg. 10:33:10

Example 2: convert_tz mysql

CONVERT_TZ(datetime, from_tz, to_tz)

Example: 
SELECT CONVERT_TZ('2031-09-21 02:42:14', 'UTC', 'America/New_York');
output: 2031-09-20 22:42:14

Example 3: mysql current date

SELECT NOW();
It returns current date and time.

Example 4: mysql current time

CURRENT_TIME return HH:ii:ss format time in mysql