At the moment, when Thunderbird sets up a reminder it gives it an absolute value i.e it uses the Timezone value in the settings. I travel between timezones frequently and so setting up a reminder for when I am in a different timezone is a problem. When setting up a reminder I would either like an option to set the timezone other than the default, or to have a relative value with no timezone setting at all and have the time apply to wherever I happen to be.