Expires string in cookie header

Question

Simple question I think, but I just can\'t seem to find an answer.

I am writing a cookie in a Java Servlet with the Cookie class which is sent to the browser in the resp

Answer 1

Java 8 now supplies an appropriate date formatter, DateTimeFormatter.RFC_1123_DATE_TIME:

OffsetDateTime oneHourFromNow 
        = OffsetDateTime.now(ZoneOffset.UTC)
        .plus(Duration.ofHours(1));

String cookieExpires 
        = DateTimeFormatter.RFC_1123_DATE_TIME
        .format(oneHourFromNow);

// E.g. "Tue, 8 Nov 2016 20:15:46 GMT"

This format is valid for the the expires attribute, see RFC 6265 § 4.1.1, which defines the format to be an RFC 1123 date:

expires-av        = "Expires=" sane-cookie-date
sane-cookie-date  =