UPD: issue was with calendar server settings, not Thunderbird. Hi. I have a corporate calendar attached to Thunderbird. Everything works more or less fine except meeting reminders. I get them before meeting - that's ok, but they have time expressed in UTC+00:00 timezone. Sad story that I live in other timezone - UTC+02:00/UTC+01:00 so need to 'recalculate' time each time. Not a big deal, however, quite annoying. Of course, all settings are set up for correct UTC+02:00 timezone ( e.g. Tools-Options-Calendar-General-Timezone ). Any advice? I'm using Thunderbird 45.1.1 + Lightning 4.7.1.1