Title: timezone problems Last modified: September 1, 2016 --- # timezone problems * Resolved [Jockel666](https://wordpress.org/support/users/jockel666/) * (@jockel666) * [9 years, 9 months ago](https://wordpress.org/support/topic/timezone-problems-4/) * In my ics file I have mixtured time zones: * `DTSTART;TZID="GMT+01.00/+02.00":20150803T130000` and `DTSTART;TZID="Europe/ Berlin":20150804T130000` * probably done by different Clients creating the events. Both time zones should mean the same time, 1pm. Whatever I try with the tz=… code, I don’t get it. WordPress timezone is “Berlin”, local time etc. is shown correctly. * When I try “tz=CET”, then both are shown with the same time, but some hours too late. When I try “tz=Europe/Berlin”, I get 1pm and 2pm. I also tried all settings of “choose date localisation method”. * Using “show_in_events_timezone=1” does not change anything. * [https://wordpress.org/plugins/amr-ical-events-list/](https://wordpress.org/plugins/amr-ical-events-list/) Viewing 5 replies - 1 through 5 (of 5 total) * Plugin Author [anmari](https://wordpress.org/support/users/anmari/) * (@anmari) * [9 years, 9 months ago](https://wordpress.org/support/topic/timezone-problems-4/#post-7691814) * Hi, There is no “GMT+01.00/+02.00” in “the” tz database [https://en.wikipedia.org/wiki/List_of_tz_database_time_zones](https://en.wikipedia.org/wiki/List_of_tz_database_time_zones) The ics RFC5545 spec ‘suggests’ that the tz database be used: [https://tools.ietf.org/search/rfc5545#section-3.2.19](https://tools.ietf.org/search/rfc5545#section-3.2.19) Php also does not have such a timezone – it uses the tz database too [http://php.net/manual/en/timezones.php](http://php.net/manual/en/timezones.php) * Some applications just do their own thing and it would appear that your first ics file is one of those. Over the years the plugin has coped with some of these oddities. EG: it will map the windows non-localised timezones, and If cities are listed, it will ‘guess’ the correct timezone. * It appears the plugin is treating it as GMT+1 (no daylight saving) and thus there would be some differences with Europe/Berlin because it does have daylight saving. * **Which application is generating the GMT TZID? Do you have control over the timezone ? Can you change it to something safer like a city based timezone? * The application may generate a timezone definition in the ICS file at the top. The plugin does not attempt to create a custom timezone from this (yet) – instead it attempts to map any strange TZID’s to the best matching php timezone. * The problem with a GMT based daylight saving change is that countries in the same longitude may NOT change DST at the same time, so what should the plugin do if it did try map it? which city based timezone would it use to get the right DST changes? * EG – these are both GMT+1 at some stage: Germany: Sunday, 27 March Sunday, 30 October Namibia: Sunday, 4 September Sunday, 3 April * More info: [http://icalevents.com/2613-what-every-developer-ought-to-know-about-timezones-wrt-calendar-files/](http://icalevents.com/2613-what-every-developer-ought-to-know-about-timezones-wrt-calendar-files/) [http://www.timeanddate.com/time/map/](http://www.timeanddate.com/time/map/) [http://www.timeanddate.com/time/dst/2016.html](http://www.timeanddate.com/time/dst/2016.html) [http://www.webexhibits.org/daylightsaving/g.html](http://www.webexhibits.org/daylightsaving/g.html) * If you don’t have control over the originating system and do have some programming skills, there is a filter ‘amr-timezoneid-filter’ that is used to do the windows mapping. You could force map the TZID? * Or pre-process the ics file, changing the TZID ? hope that helps * Thread Starter [Jockel666](https://wordpress.org/support/users/jockel666/) * (@jockel666) * [9 years, 8 months ago](https://wordpress.org/support/topic/timezone-problems-4/#post-8186642) * Hi, * the application which is creating these timezones is… Android… we have several entries made by several android devices and no common details (different apps used, different models and versions). All sync to a Zimbra server, some by Activesync, some by CalDAV. * Ah, yes, there is information in the header, and it looks the same than the following Europe/Berlin, only one detail at the DST start is different, the BYDAY is -1SU vs. 4SU which is the same in most marchs I hope 🙂 * As we can’t change Android being used, I try your other solutions, thanx! * BEGIN:VTIMEZONE TZID:GMT+01.00/+02.00 BEGIN:STANDARD DTSTART:16010101T030000 TZOFFSETTO:+0100 TZOFFSETFROM:+0200 RRULE:FREQ=YEARLY;INTERVAL=1;BYMONTH=10;BYDAY =-1SU;WKST=MO END:STANDARD BEGIN:DAYLIGHT DTSTART:16010101T020000 TZOFFSETTO: +0200 TZOFFSETFROM:+0100 RRULE:FREQ=YEARLY;INTERVAL=1;BYMONTH=3;BYDAY=4SU;WKST =MO END:DAYLIGHT END:VTIMEZONE BEGIN:VTIMEZONE TZID:Europe/Berlin BEGIN:STANDARD DTSTART:16010101T030000 TZOFFSETTO:+0100 TZOFFSETFROM:+0200 RRULE:FREQ=YEARLY; WKST=MO;INTERVAL=1;BYMONTH=10;BYDAY=-1SU TZNAME:CET END:STANDARD BEGIN:DAYLIGHT DTSTART:16010101T020000 TZOFFSETTO:+0200 TZOFFSETFROM:+0100 RRULE:FREQ=YEARLY; WKST=MO;INTERVAL=1;BYMONTH=3;BYDAY=-1SU TZNAME:CEST END:DAYLIGHT END:VTIMEZONE * Greetings, Joerg * Thread Starter [Jockel666](https://wordpress.org/support/users/jockel666/) * (@jockel666) * [9 years, 8 months ago](https://wordpress.org/support/topic/timezone-problems-4/#post-8186969) * Hi, * btw: It seems only Zimbra does not realise these strange TZID strings. Google Calendar changes them to standard IDs so the problem does not occur. * But thanx to your hint, now it works, even with the cheap solution as all our TZIDs are local 😉 * function repair_timezoneid( $tzid ) { return “Europe/Berlin”; } add_filter( ‘ amr-timezoneid-filter’, ‘repair_timezoneid’ ); * Bye, Joerg * Plugin Author [anmari](https://wordpress.org/support/users/anmari/) * (@anmari) * [9 years, 8 months ago](https://wordpress.org/support/topic/timezone-problems-4/#post-8188558) * Glad you got it sorted for you. * Googling android timezones, I still didn’t see the GMT+01.00/+02.00 listed. I found this: [https://gist.github.com/mtrung/a3f7caaa7e674ac7e6c4](https://gist.github.com/mtrung/a3f7caaa7e674ac7e6c4)– looks like the usual list * Possibly it’s an application, not android itself? Possibly in the app maybe one could choose a more useful tz? * RE the daylight saving change definitions, they are similar BUT depending on the year could be different. BYMONTH=3;BYDAY=-1SU – the last sunday of the 3rd month BYMONTH=3;BYDAY=4SU – the fourth sunday * I guess google must be assuming the Europe/Berlin is more likely to be the correct daylight saving change! * Thread Starter [Jockel666](https://wordpress.org/support/users/jockel666/) * (@jockel666) * [9 years, 8 months ago](https://wordpress.org/support/topic/timezone-problems-4/#post-8188926) * Hi, * this happens even with the build-in calendar app from Google. * Further investigation hints that it is a misunderstanding between Zimbra and Android: When I choose another Timezone far away from Berlin on Android, Zimbra shows it correctly. When I choose one of the +1/+2 zones like Berlin, Bruxelles, Windhoek, even Zimbra itself shows the strange GMT+1/+2 string. Strange too that Android seems to be the only system making these strange events, and all other( tested) clients are doing better. * So I’ll contact our server admins, maybe its a configuration thing in Zimbra or the underlying system. * (My guess is: Android is sending the correct “Berlin” string. Zimbra (other than e.g. the Google Server) is checking the definition of the TZ-definitions, is seeing the difference in BYDAY and then is thinking that “Berlin” is wrong and then is giving these events a self-created “special” time zone. But I have no idea, why only the +1/+2 timezones are affected, and why only android-events…) * Thanx again, greetings, Joerg Viewing 5 replies - 1 through 5 (of 5 total) The topic ‘timezone problems’ is closed to new replies. * ![](https://s.w.org/plugins/geopattern-icon/amr-ical-events-list_f5f4f4.svg) * [amr ical events lists](https://wordpress.org/plugins/amr-ical-events-list/) * [Support Threads](https://wordpress.org/support/plugin/amr-ical-events-list/) * [Active Topics](https://wordpress.org/support/plugin/amr-ical-events-list/active/) * [Unresolved Topics](https://wordpress.org/support/plugin/amr-ical-events-list/unresolved/) * [Reviews](https://wordpress.org/support/plugin/amr-ical-events-list/reviews/) * 5 replies * 2 participants * Last reply from: [Jockel666](https://wordpress.org/support/users/jockel666/) * Last activity: [9 years, 8 months ago](https://wordpress.org/support/topic/timezone-problems-4/#post-8188926) * Status: resolved