If a cache receives a value larger than the largest positive integer it can represent, or if any of its age calculations overflows, it MUST transmit an Age header with a value of 2147483648 (2^31)
Max-Age=value
OPTIONAL. The value of the Max-Age attribute is delta-seconds,
the lifetime of the cookie in seconds, a decimal non-negative
integer. To handle cached cookies correctly, a client SHOULD
calculate the age of the cookie according to the age calculation
rules in the HTTP/1.1 specification [RFC2616]. When the age is
greater than delta-seconds seconds, the client SHOULD discard the
cookie. A value of zero means the cookie SHOULD be discarded
immediately.