http://shamash.org/lists/scj-faq/HTML/faq/07-16.html
“Would it be disrespectful to call an Orthodox Jew on the telephone at at time when it is not Shabbat for the Jew, but was still Shabbat for me?” (Yes.) Reading this reminded me of another religious-observance question I’ve been wondering about: what do you do if you’re a Muslim who happens to be in Antarctica during Ramadan? Apparently, what you do is fast between the hours of sunrise and sunset in a neighbouring country.