tzdata is merely data. It doesn't *do* anything, and certainly doesn't magically change the time. It contains information on how to convert system time (UTC offset from the UNIX epoch) into the correct localtime, based on your $TZ selection or /etc/localtime, but it's up to applications displaying the time to actually call into the correct libc functions to give you an appropriate time.
Usually where this goes wrong is that people will ask glibc for a correct time once on startup, and then start an internal counter and increment that, never going back to check on reality. Common fixes for this that don't cause intense load tend to be things like only checking localtime when each minute ticks over, or only checking when an application is actually displayed in the foreground. Obviously, the latter would be completely wrong for an alarm clock, and the former would cause unwanted wakeups on a phone, but one could be clever and ask about future stamps in advance, if you're setting up wakeup events. ie: Ask the system to mktime your next alarm time (or next N alarm times) and store the correct wakeup events as neutral timestamps, so that even if DST happens while you're asleep, the next alarm happens correctly anyway. ** Package changed: tzdata (Ubuntu) => ubuntu-clock-app -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to tzdata in Ubuntu. https://bugs.launchpad.net/bugs/1437805 Title: Time didn't change itself after Daylight Saving Time started in Edinburgh Status in Clock application for Ubuntu devices: New Bug description: Today (29/03/2015) at 7:59 in the morning I've noticed the clock on my bq phone shows 6:59. I remember setting the time zone to "Edinburgh" when setting the phone. Today, when I opened the clock app I've seen this [1]. You can also notice that time for Warsaw is correct. Then I went to time and date settings. It displayed "UTC+0". I set "Time zone:" to Edinburgh again. After that it showed "UTC+1" and time was correct. I must add that yesterday I set alarm on another device (Android phone) which thankfully woken me up on the right time. Otherwise my son's football training would be missed. [1] see the attached screenshot, please. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-clock-app/+bug/1437805/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : [email protected] Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
