Max value for cache control header in HTTP

Question

I\'m using Amazon S3 to serve static assets for my website. I want to have browsers cache these assets for as long as possible. What meta-data headers should I include with

Answer 1

Consider not storing it for "as long as possible," and instead settling for as long as reasonable. For instance, it's unlikely you'd need to cache it for longer than say 10 years...am I right?

The RFC discusses max-age here: http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.9.3

Eric Lawrence says that prior to IE9, Internet Explorer would treat as stale any resource with a Cache-Control: max-age value over 2147483648 (2^31) seconds, approximately 68 years (http://blogs.msdn.com/b/ie/archive/2010/07/14/caching-improvements-in-internet-explorer-9.aspx).

Other user agents will of course vary, so...try and choose a number that is unlikely (rather than likely!) to cause an overflow. Max-age greater than 31536000 (one year) makes little sense, and informally this is considered a reasonable maximum value.