How a Time Zone Change Could Break Your Apps

Most people think of time zones as &ldquo;offsets from UTC&rdquo;, but we know they&rsquo;re more than that: they also include rules, like when to switch to summer time, and the historical rules and offsets. If Europe removes the DST switch, Europe/Madrid would, for example, transition from a two-rule timezone (UTC+1 in winter, UTC+2 in summer) to a single offset. That means new data in the IANA…