Patent ID: 7932823

Claim:
A system for providing a notice of a disaster comprising: at least one terminal; a server providing information related to said disaster for said terminal; wherein said server comprises: a first time measuring unit which measures a server current time, a first calculating unit which calculates an expected time of arrival of said disaster at said terminal in case said disaster happens, a checking time calculating unit which calculates a checking time for checking accuracy of a terminal current time, and a transmitting unit which transmits said expected time and said checking time to said terminal wherein said terminal comprises: a second time measuring unit which measures the terminal current time, a second calculating unit which calculates the time remaining until said disaster arrives at said terminal based on said expected time and said checking time, wherein said checking time calculating unit obtains said server current time when said disaster happens, calculates a first difference between said server current time and the time said disaster happened, and calculates said checking time based on said first difference if said first difference exceeds a first threshold, and wherein said second calculating unit obtains said terminal current time when receiving said expected time and said checking time, calculates a second difference between said terminal current time and said checking time, and calculates said remaining time based on said expected time and said terminal current time if said second difference does not exceed a second threshold, and calculates said remaining time based on said expected time and said checking time if said second difference exceeds said second threshold.