SQL Date function

1. Day (date_expression)
Returns the date value in Date_expression

2. Month (date_expression)
Returns the month value in Date_expression

3. Year (date_expression)
Returns the year value in Date_expression

4, DATEADD ()
DATEADD (<DATEPART>, <number>, <date>)
Returns the new date specified by date plus the specified extra date interval number.
5, DATEDIFF ()
DATEDIFF (<DATEPART>, <date1>, <date2>)
Returns the DATEPART difference between the two specified dates, that is, the date2 exceeds the value of date1, and the resulting value is an integer value with a positive sign.

6, Datename ()
Datename (<DATEPART>, <date>)
Returns the specified part of the date as a string in this section. specified by DatePart.

7, DATEPART ()
DATEPART (<DATEPART>, <date>)
Returns the specified part of the date as an integer value. This section is specified by DatePart.
DATEPART (dd, date) is equivalent to day (date)
DATEPART (mm, date) equals month (date)
DATEPART (yy, date) is equivalent to year (date)

8, GETDATE ()
Returns the current date and time of the system in the default format of datetime

SQL Date function