Generally, I think the best approach is to: 1. Store UTC datetimes and do all calculations in UTC (or Unix epochs) 2. Store the timezone separately 3. When r

Generally, I think the best approach is to: 1. Store UTC datetimes and do all calculations in UTC (or Unix epochs) 2. Store the timezone separately 3. When rendering dates/times in the UI, convert the UTC datetimes to local dates/times. I forgot where I first saw this recommended. I think it's recommended in a lot of places, though.