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

The people who created the recommendation of maximum 1 year caching did not think it through properly.

First of all, if a visitor is being served an outdated cached file, then why would it provide any benefit to have it suddenly load a fresh version after 1 year? If a file has 1 year TTL, from a functional perspective, it obviously means that the file is not intended to be changed at all.

So why would one need more than 1 year?

1) Why not? It doesn't server any purpose to tell the visitors browser "hey, this file is 1 year old, it might be an idea to check if it has been updated".

2) CDN services. Most content delivery networks use the cache header to decide how long to serve a file efficiently from the edge server. If you have 1 year cache control for the files, it will at some point start re-requesting non-changed files from the origin server, and edge-cache will need to be entirely re-populated, causing slower loads for client, and unnecessary calls to the origin.

What is the point of having max 1 year? What browsers will choke on an amount set higher than 31536000?