/// <summary>
/// Matches a request by HTTP header on a datetime value (per RFC-2616).
/// </summary>
/// <param name="builder">The request matching builder instance.</param>
/// <param name="name">The header name.</param>
/// <param name="date">The header value.</param>
/// <returns>The request matching builder instance.</returns>
public static RequestMatching Header(this RequestMatching builder, string name, DateTimeOffset date)
{
// https://tools.ietf.org/html/rfc2616#section-3.3.1
CultureInfo ci = CultureInfo.InvariantCulture;
#if NETFRAMEWORK
// .NET Framework does not normalize other common date formats,
// so we use multiple matches.
return(builder.Any(any => any
.Header(name, date.ToString("R", ci))
.Header(name, date.ToString("dddd, dd-MMM-yy HH:mm:ss 'GMT'", ci)) // RFC 1036
.Header(name, date.ToString("ddd MMM d H:mm:ss yyyy", ci)) // ANSI C's asctime()
));
#else
return(builder.Header(name, date.ToString("R", ci)));
#endif
}