# SUBTRACT\_YEARS ### Description `SUBTRACT_YEARS` takes a date, from either an information or in [ISO8601 format](/rule-language/operators/date-operators.md), and a number of years to subtract, and returns a date with the given number of years subtracted. In the special case that the new year doesn't contain the original date (e.g. when subtracting a year from the leap day 29.02.2016) the new date will have the same number of days from the beginning of the year (e.g. 01.03.2015 in the earlier example). ### Example: Date ``` SUBTRACT_YEARS(NOW(), 18) ``` This expression returns the current date 18 years ago. ``` SUBTRACT_YEARS('2000-01-01, 18) ``` This returns the 1st January 1982 ### Example: Date with time If you specify not just a date, but a date and time in ISO8601 format, the function includes the time in the calculation. ``` SUBTRACT_YEARS('2000-01-01T09:35:23', 18) ``` This returns also the 1st January 1982, but at 9:35:23, so `1982-01-01T09:35:23`. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.atfinity.io/rule-language/operators/date-operators/subtract_years.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.