MYSQL:

-- current date

SELECT CURRENT_DATE AS date_current_date;

-- start of last week (begin: monday)

SELECT DATE_ADD(DATE_ADD(CURRENT_DATE, INTERVAL -WEEKDAY(CURRENT_DATE) DAY), INTERVAL -1 WEEK) AS start_of_last_week;

-- end of last week (begin: monday)

SELECT DATE_ADD(DATE_ADD(CURRENT_DATE, INTERVAL -WEEKDAY(CURRENT_DATE)+6 DAY), INTERVAL -1 WEEK) AS end_of_last_week;

-- start of current week (begin: monday)

SELECT DATE_ADD(CURRENT_DATE, INTERVAL -WEEKDAY(CURRENT_DATE) DAY) AS start_of_current_week;

-- end of current week (begin: monday)

SELECT DATE_ADD(CURRENT_DATE, INTERVAL -WEEKDAY(CURRENT_DATE)+6 DAY) AS end_of_current_week;

-- start of next week (begin: monday)

SELECT DATE_ADD(DATE_ADD(CURRENT_DATE, INTERVAL -WEEKDAY(CURRENT_DATE) DAY), INTERVAL 1 WEEK) AS start_of_next_week;

-- end of next week (begin: monday)

SELECT DATE_ADD(DATE_ADD(CURRENT_DATE, INTERVAL -WEEKDAY(CURRENT_DATE)+6 DAY), INTERVAL 1 WEEK) AS end_of_next_week;

-- start of last month

SELECT DATE_ADD(MAKEDATE(YEAR(CURRENT_DATE), 1), INTERVAL MONTH(CURRENT_DATE)-2 MONTH) AS start_of_last_month;

-- end of last month

SELECT DATE_ADD(DATE_ADD(MAKEDATE(YEAR(CURRENT_DATE), 1), INTERVAL MONTH(CURRENT_DATE)-1 MONTH), INTERVAL -1 DAY) AS end_of_last_month;

-- start of current month

SELECT DATE_ADD(MAKEDATE(YEAR(CURRENT_DATE), 1), INTERVAL MONTH(CURRENT_DATE)-1 MONTH) AS start_of_current_month;

-- end of current month

SELECT DATE_ADD(DATE_ADD(MAKEDATE(YEAR(CURRENT_DATE), 1), INTERVAL MONTH(CURRENT_DATE) MONTH), INTERVAL -1 DAY) AS end_of_current_month;

-- start of next month

SELECT DATE_ADD(MAKEDATE(YEAR(CURRENT_DATE), 1), INTERVAL MONTH(CURRENT_DATE) MONTH) AS start_of_next_month;

-- end of next month

SELECT DATE_ADD(DATE_ADD(MAKEDATE(YEAR(CURRENT_DATE), 1), INTERVAL MONTH(CURRENT_DATE)+1 MONTH), INTERVAL -1 DAY) AS end_of_next_month;

-- start of last year

SELECT MAKEDATE(YEAR(CURRENT_DATE)-1, 1) AS start_of_last_year;

-- end of last year

SELECT DATE_ADD(MAKEDATE(YEAR(CURRENT_DATE), 1), INTERVAL -1 DAY) AS end_of_last_year;

-- start of current year

SELECT MAKEDATE(YEAR(CURRENT_DATE), 1) AS start_of_current_year;

-- end of current year

SELECT DATE_ADD(MAKEDATE(YEAR(CURRENT_DATE)+1, 1), INTERVAL -1 DAY) AS end_of_current_year;

-- start of next year

SELECT MAKEDATE(YEAR(CURRENT_DATE)+1, 1) AS start_of_next_year;

-- end of next year

SELECT DATE_ADD(MAKEDATE(YEAR(CURRENT_DATE)+2, 1), INTERVAL -1 DAY) AS end_of_next_year;