Abstract: A pocket sized portable information device provides an alarm indicating Moslem prayer times. Means are provided for entering information identifying geograpical location, from which the hours of sunrise and sunset are calculated and then the prayer times. The device includes an oscillator driving a clock calendar and an interrupt time both of which are linked to a microprocessor. Codes identifying geographical locations are input via suitable key pads, resulting in geographical co-ordinate information being supplied to the microprocessor from a location ROM. By means of suitable algorithms the microprocessor calculates sunrise, sunset and the prayer times, and at the appropriate times provides an audible alarm through an amplifier and a transducer (T). The device is also provided with a compass identifying the direction towards magnetic north. Using the information from the location ROM the microprocessor calculates the deviation from magnetic north to the direction towards Mecca for the location concerned.