bluehoursite.com
Blue Hour | Night Photography

I made a minor update today in the blue hour calculator. I got a message from a visitor about missing data for the Antarctic region. I thought the best would be to include the research stations. So now if you plan to travel down to the south pole for some good blue hour photographs don't forget to check the best time to do it. Anyway I'm not sure about the accuracy at the moment so it is still in testing phase. As you know there are time periods when sun goes below horizon and when sun shines all day long for different areas so this may affect the calculations. The system uses two states for this: "Dark" and "Light". I'll probably improve this more a bit after doing some research and fine tuning.

Also there is an another improvement, now you can see the actual Time Zone for the location you looking for. Blue hour calculator automatically applies the daylight saving time when it is used in the area.