MapDiary now correctly calculates and displays local times based on the actual geographical location of your posts. This feature currently relies on the free Geonames web service which can be a bit unstable at times (a fact I found out the hard way...), thus when this service is unavailable the application falls back on the time zone set in your Twitter settings. Thanks to everyone currently using MapDiary! Seeing posts pop up from all corners of the world on my little app is great fun. :)