## Purpose

Declares an INTERVAL YEAR TO MONTH value in an expression.

## Syntax

- sign
- An optional minus sign to indicate a negative interval. The default is a positive interval.
- string
- One to four digits representing the number of years, followed by a hyphen and two digits representing the number of months. Spaces and new line characters are not allowed between the apostrophes.For the digits representing the number of years, only digits are parsed and converted to numeric. For example, '1.05' is treated as '105'.

## ANSI Compliance

INTERVAL YEAR TO MONTH literals are partly ANSI SQL:2011 compliant.

The ANSI definition places the optional sign for the interval within the apostrophes; the Teradata implementation places the optional sign outside the apostrophes.

## Type

INTERVAL YEAR TO MONTH

For details on the INTERVAL YEAR TO MONTH type, see INTERVAL YEAR TO MONTH Data Type.

## Examples: INTERVAL YEAR TO MONTH Literal

The following example adds an interval of two years and six months to the current system date. (For this example, assume the current system date is 1999-11-03.)

SELECT CURRENT_DATE + INTERVAL '2-06' YEAR TO MONTH; ( 2-06+Date) -------------- 2002/05/03

In the following query, the decimal point is ignored and the result is an interval of 10 years and 10 months.

SELECT INTERVAL '1.0-10' YEAR TO MONTH;