The calendar in Thunderbird works rather well, however I find I need to make a modification to the 'Reminder' interface. The 'Reminder' options have nice usable minute increments, but then jump from 30 min. to 1-Hour. I used to be able to travel from my location to most assignment within 30 minutes, this would get me to the assignment a few minutes ahead of schedule. Now, because of traffic, I need to leave at 45 minutes before the assignment. I can create a custom reminder for 45-minutes, but it will not stick for the next new event. How can I make a 45-minute reminder that I can use for any new event?