# Date Operators Date operators allow you to handle information concerning time. You can use them to set or calculate a moment in time, determine the number of days in between two dates or format how a date should be displayed. ### ISO8601 Format ISO8601 is the international standard format for date or a date and time ([wikipedia](https://en.wikipedia.org/wiki/ISO_8601)). The values are ordered from the largest unit of time to the smallest: year, month, day, hour, minute and second. #### Date A date is given as `YYYY-MM-DD`, for example `2016-02-29` (the founding date of Atfinity AG). #### Time and Date If you need a date with a time, the format would be `YYYY-MM-DDThh-mm-ss`, so a date and a time separated by a `T`. For example`1999-06-25T09:52:08`. #### Using ISO8601 If dates are given to Atfinity as text, they always need to be in ISO8601 format. If a function in Atfinity returns a date, it will always be in ISO8601 format. If you want to return anything from Atfinity in a different format you can use [FORMAT\_DATE](/rule-language/operators/date-operators/format_date.md) to format the output to your liking. --- # 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.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.