Help Center> Data Lake Insight> Spark SQL Syntax Reference> Built-In Functions> Date Functions> add_months
Updated on 2023-10-25 GMT+08:00
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add_months

This function is used to calculate the date after a date value is increased by a specified number of months. That is, it calculates the data that is num_months after start_date.

Syntax

add_months(string start_date, int num_months)

Parameters

Table 1 Parameters

Parameter

Mandatory

Type

Description

start_date

Yes

DATE or STRING

Start date

The following formats are supported:

  • yyyy-mm-dd
  • yyyy-mm-dd hh:mi:ss
  • yyyy-mm-dd hh:mi:ss.ff3

num_months

Yes

INT

Number of months to be added

Return Values

The date that is num_months after start_date is returned, in the yyyy-mm-dd format.

The return value is of the DATE type.

  • If the value of start_date is not of the DATE or STRING type, the error message "data type mismatch" is displayed.
  • If the value of start_date is of the DATE or STRING type but is not in one of the supported formats, NULL is returned.
  • If the value of start_date is NULL, an error is reported.
  • If the value of num_months is NULL, NULL is returned.

Example Code

The value 2023-05-26 is returned.

select add_months('2023-02-26',3);

The value 2023-05-14 is returned.

select add_months('2023-02-14 21:30:00',3);

The value NULL is returned.

select add_months('20230815',3);

The value NULL is returned.

select add_months('2023-08-15 20:00:00',null);
Parent topic: Date Functions