Pray on PlaneEver since building the Zmanim (Jewish times) feature in the iPhone Siddur I have been intrigued by the algorithms that go into calculating these times. For those of you who are programmers, there is an open source project on this at KosherJava where you can dig into that code.

I am flying to Israel soon and one topic that comes up when you fly at certain hours is when can you pray. In fact, there was a story recently about an emergency landing due to praying on a flight. But if you can get away with praying on a plane, the question for a Jew is when can you do so?

When you are standing in a single place, it is simple, because you are not streaming through time and space at 500 miles per hour. You are not jumping from one time zone to another and you are getting a full cycle of sunrise and sunset.

I was recently told about a web site that lets you plug in your departing airport and destination airport, the times, the airline and it then tells you, based on the standard flight path, what times you can pray. The web page is Chai Air Tables and it tells you, based on your take off time (if there is a delay, it accounts for it) when you can pray certain prayers.

This is pretty cool, in my opinion.