Use of mysql Stored Procedure time functions

Let's start with a common example:

1. Get the current time and format it.

DECLARE I INT;
SET I = date_format (now (), '% Y % m % D ');

ADDTIME (date2, time_interval) // Add time_interval to date2

CONVERT_TZ (datetime2, fromTZ, toTZ) // convert the time zone
CURRENT_DATE () // current date
CURRENT_TIME () // current time
CURRENT_TIMESTAMP () // current Timestamp

DATE (datetime) // return the DATE part of datetime
DATE_ADD (date2, INTERVAL d_value d_type) // Add a date or time in date2
DATE_FORMAT (datetime, FormatCodes) // display datetime in formatcodes format
DATE_SUB (date2, INTERVAL d_value d_type) // subtract a time from date2
DATEDIFF (date1, date2) // two date differences

DAY (date) // returns the DAY of the date
DAYNAME (date) // english week
DAYOFWEEK (date) // Week (1-7), 1 is Sunday
DAYOFYEAR (date) // The day of the year
EXTRACT (interval_name FROM date) // EXTRACT the specified part of the date FROM date

Makedate (year, day) // specifies the day of the year and year to generate a date string.
Maketime (hour, minute, second) // generate a time string
Monthname (date) // name of the English month
Now () // current time
Sec_to_time (seconds) // converts seconds to time

Str_to_date (string, format) // convert string to time, which is displayed in format
Timediff (datetime1, datetime2) // two time difference
Time_to_sec (time) // time to seconds]
Week (date_time [, start_of_week]) // week
Year (datetime) // year

Dayofmonth (datetime) // The day of the month
Hour (datetime) // hour
Last_day (date) // the last date of the Month of date
Microsecond (datetime) // microsecond
Month (datetime) // month
Minute (datetime) // minute