Ekadasi Tithi and Time in India will not be same as that of United States and that of Singapore. Each country has a different time for Ekadashi fasting. To calculate the Ekadasi time in your region you need to know the following facts – 1) time difference from India and your present residing country. 2) You need to know the sunrise time in your country.
The Ekadasi calculator and the software is provided by Sri Ahobila Mutt.