description: If you consider new functions then much common will be
Of course it's just a suggestion of a name and syntax,

MODIFY_DATE([SET] {DAY | MONTH | YEAR } <value> FOR <date or timestamp>)

MODIFY_DATE(DAY 1 FOR '2017-09-22') -- 2017-09-01
MODIFY_DATE(MONTH 1 FOR '2017-09-22') -- 2017-01-27
MODIFY_DATE(YEAR 2000 FOR '2017-09-22') -- 2000-09-22

and

MODIFY_TIME([SET] {HOUR | MINUTE | SECOND | MILLISECOND } <value> FOR <date or timestamp>)

MODIFY_TIME(HOUR 15 FOR '08:06:22') -- '15:06:22'
MODIFY_TIME(MINUTE 15 FOR '08:06:22') -- '08:15:22'
MODIFY_TIME(SECOND 1 FOR '08:06:22') -- '08:06:01'
...

maybe name should be RECODE_DATE, REPLACE_DATE...

=>

If you consider new functions then much common will be
Of course it's just a suggestion of a name and syntax,

MODIFY_DATE([SET] {DAY | MONTH | YEAR } <value> FOR <date or timestamp>)

MODIFY_DATE(DAY 1 FOR '2017-09-22') -- 2017-09-01
MODIFY_DATE(MONTH 1 FOR '2017-09-22') -- 2017-01-22
MODIFY_DATE(YEAR 2000 FOR '2017-09-22') -- 2000-09-22

and

MODIFY_TIME([SET] {HOUR | MINUTE | SECOND | MILLISECOND } <value> FOR <date or timestamp>)

MODIFY_TIME(HOUR 15 FOR '08:06:22') -- '15:06:22'
MODIFY_TIME(MINUTE 15 FOR '08:06:22') -- '08:15:22'
MODIFY_TIME(SECOND 1 FOR '08:06:22') -- '08:06:01'
...

maybe name should be RECODE_DATE, REPLACE_DATE...