| 摘要 |
An Input of a calendar and a selection of an area are made from an input unit ; in a CPU , the positions of the heavenly bodies are calculated from the calendar to calculate the moon age value; tidal data corresponding to the selected area are read out from a ROM stored with the tidal data for each area; and a tentative spring tide day is determined by adding the tidal data to the new moon day and the full moon day, as determined from the moon age value, so that when the tentative spring tide day Is the day to appear at first on and after the calendar, this day Is calculated as the true spring tide day. As a result, it is possible to accurately determine the spring tide day intrinsic between the areas. <IMAGE> |
