Dear sir I would be grateful for your assistance. I obtained your E Mail address from Paul Stewart's web page. I am working on earthquakes which are recorded on UT time tied in with Zone Time. My problem is that I need to get the "real time" of these events, the time that it takes from Greenwich to reach the longitude by the Earths rotation. I need to tie up time and longitude, the earthquakes are reported in position of longitude / latitude, but not as accurately as time. I also need the real time span between quakes. My ideal solution to this problem would be software that would take in a spreadsheet produced file ( I have thousands of quakes ) and analysing date, time and latitude / longitude produce exact "real time" / Earth rotation time. I write my own spreadsheet macro's (Aseasy As)and could construct one if I knew all the time / zone boundary parameters. From what I have surmised of the crazy Zone and different clock contortions this would be a big job. I do not write macro's for Excel or Lotus 123 but could work existing macro sheets if they were available. I hope you can help me as I cannot move forward till I have solved this problem. Yours sincerely Jim Affleck j.h.affleck@tesco.net