- SQL Interval Format
The format for an interval year to month is [+ | -]YY-MM. YY is an integer between 0 and 9999, and MM is an integer between 0 and 11.
- ISO Duration Format
The format for a duration is [-]P[n]Y[n]M[n] where n specifies the value of the element (for example, 4Y is 4 years).
This represents a subset of the ISO duration format and the use of any arguments other than P, Y, and M are ignored. Leading and trailing zeroes are optional. Spaces are not allowed within the element format. Elements may be omitted if they are zero, but at least one element and its number is required.
A leading negative sign denotes a negative interval. If omitted, the interval is positive. A positive sign is not allowed.
Element values are integers between 0 and any value that will not cause an interval overflow. The values can exceed their normal time limit. For example, P14M represents 14 months, even though there are 12 months in a year. The ISO duration letter designators have the following meaning (only the P, Y, and M designators are allowed for the YEAR to MONTHS interval):
ISO Designator Definition P Duration. It is always at the beginning. Y Year. It follows the number of years. M Month. It follows the number of months. You can also pass arguments with data types that can be converted to the above types using the implicit data type conversion rules that apply to UDFs.
The UDF implicit type conversion rules are more restrictive than the implicit type conversion rules normally used by Teradata Database. If an argument cannot be converted to the required data type following the UDF implicit conversion rules, it must be explicitly cast.