# Last-Modified The Last-modified header is an HTTP response header that contains the date and time when the origin server believes the resource was last modified. It is used as a validator to determine if the resource is the same as the previously stored one. It is less accurate than an ETag header, but it can be a fallback mechanism. Conditional requests containing If-Modified-Since or If-Unmodified-Since headers make use of this field. --- # 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.transparentedge.eu/getting-started/faq/glosario/last-modified.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.