This may be a misunderstanding on my part about the file formats of zone.tab and zone1970.tab and how consistent they are expected to be. I expect the exact zone IDs to be different, but there are only a few cases where countries differ in the number of referenced zone IDs. I realize that zone.tab is intended for backward compatibility but it looks like it is being well maintained. Is this difference expected? If it is, can somebody explain? Details below the line. Thanks for all the hard work. Neil. ------------------- 2017b: TF zone.tab: TF -492110+0701303 Indian/Kerguelen zone1970.tab: RE,TF -2052+05528 Indian/Reunion Réunion, Crozet, Scattered Islands TF -492110+0701303 Indian/Kerguelen Kerguelen, St Paul Island, Amsterdam Island ------------------ UM zone.tab: UM +2813-17722 Pacific/Midway Midway Islands UM +1917+16637 Pacific/Wake Wake Island zone1970.tab: AS,UM -1416-17042 Pacific/Pago_Pago Samoa, Midway UM +1917+16637 Pacific/Wake Wake Island US,UM +211825-1575130 Pacific/Honolulu Hawaii ------------------ VN zone.tab: VN +1045+10640 Asia/Ho_Chi_Minh zone1970.tab: TH,KH,LA,VN +1345+10031 Asia/Bangkok Indochina (most areas) VN +1045+10640 Asia/Ho_Chi_Minh Vietnam (south) -- Google UK Limited Registered Office: 6 Pancras Square, London, N1C 4AG Registered in England Number: 3977902