Abstract: Means are provided for inputting to an electronic computing device the latitude and longitude of a spot on the surface of the Earth, and also for inputting a date, and the computing device then calculates the proper Islamic prayer times at said spot on said date, via determining the position of the sun in the heavens, according to said date and said latitude and longitude information. Then an outputting means outputs from said electronic computation means said appropriate times for Islamic prayer on said date at said spot on the surface of the Earth. Optionally a clock/date circuit and an audible indicator are provided, so that the electronic computing device can automatically know the time and the date, and can sound a call for prayer for the operator at each of the Islamic prayer times on the current day.