>If I record that upcoming datetime in UTC but I forgot about a daylight savings time change between now and then that doesn't mean the event will happen at 6pm

>If I record that upcoming datetime in UTC but I forgot about a daylight savings time change between now and then that doesn't mean the event will happen at 6pm - it's still happening at 7. This breaks down when you start having to deal with multiple timezones. Then whenever you do sorting or availability checks you have to account for DST/timezones. You will pretty quickly make a method that converts your timezone stored data to UTC. Better to just store it all as UTC so that your DB queries are much simpler.