| Syntax: | expires [ modified ] time expires epoch | max | off |
| Default: | off |
| Context: | http server location if in location |
| Reference: | expires |
Controls whether the response should be marked with an expiry time, and if so, what time that is.
off prevents changes to the Expires and Cache-Control headers. epoch sets the Expires header to 1 January, 1970 00:00:01 GMT. max sets the Expires header to 31 December 2037 23:59:59 GMT, and the Cache-Control max-age to 10 years. @ prefix specifies an expiry time relative to either the response time (if the time is not preceded with "modified") or the file's modification time (when "modified" is present — available from versions 0.7.0 & 0.6.32). A negative time can be specified, which sets the Cache-Control header to no-cache. @ prefix represent an absolute time-of-day expiry, written in either the form Hh or Hh:Mm, where H ranges from 0 to 24, and M ranges from 0 to 59 (available from versions 0.7.9 & 0.6.34). A non-negative time or time-of-day sets the Cache-Control header to max-age = #, where # is the appropriate time in seconds.
Note: expires works only for 200, 204, 301, 302, and 304 responses.