27253 2014-11-05 21:22:46 +0000 Confusions involving Universal Time and old time stamps 2016-04-27 19:44:20 +0000 1 1 1 Unclassified HTML WG HTML5 spec unspecified All All RESOLVED FIXED P2 normal --- 1 eggert dave.null arronei mike public-html-admin public-html-wg-issue-tracking public-html-bugzilla oldest_to_newest 114566 0 1534 eggert 2014-11-05 21:22:46 +0000 Created attachment 1534 Fix some confusions involving Universal Time and old time stamps. The HTML5 spec requires UT1 for pre-UTC time stamps, but in practice UT2 was the basis of civil timekeeping just before UTC was inaugurated, and UT0 is a better choice than UT1 if you go back far enough. But the main point is that the HTML standard shouldn't try to impose a "must" time standard here (UT1 vs UT2 vs whatever) when this doesn't correspond to common practice. Instead, the standard should simply call out Universal Time as a general term. A proposed patch is attached. Some other minor changes for this edit: * Change a couple of "must"s to "should"s when "must" is too strong. * Mention that UT is mean solar time, not solar time. * Don't require actual observations at Greenwich for old time stamps -- if you go back far enough, nobody was at Greenwich to observe anything. My source for UT2 being the basis of civil timekeeping just before UTC is the following email from Steve Allen of UCO/Lick Observatory: http://mm.icann.org/pipermail/tz/2014-November/021867.html He cites the Bulletin Horaire of the Bureau International de l'Heure, March-April 1960, which is archived here: https://plus.google.com/photos/112320138481375234766/albums/6078225731350227361 126219 1 arronei 2016-04-27 19:44:20 +0000 HTML5.1 Bugzilla Bug Triage: Fixed, The term "must" is necessary in order to get a consistent conversion across browsers with a consistent format. I see no need to change this. However, I have added "mean" solar time and clarified that the Greenwich is the location of Greenwich not specifically the city but the "location". https://github.com/w3c/html/pull/275 If this resolution is not satisfactory, please copy the relevant bug details/proposal into a new issue at the W3C HTML5 Issue tracker: https://github.com/w3c/html/issues/new where it will be re-triaged. Thanks! 1534 2014-11-05 21:22:46 +0000 2014-11-05 21:22:46 +0000 Fix some confusions involving Universal Time and old time stamps. 0001-Fix-some-confusions-involving-Universal-Time-and-old.patch text/plain 2756 eggert RnJvbSAzYWQ0ZTU4ODBlOTlhMjE3YmJmY2VjODRmZGZjZWNjYmM2NDVmZTk3IE1vbiBTZXAgMTcg MDA6MDA6MDAgMjAwMQpGcm9tOiBQYXVsIEVnZ2VydCA8ZWdnZXJ0QGNzLnVjbGEuZWR1PgpEYXRl OiBXZWQsIDUgTm92IDIwMTQgMTI6NTc6NTEgLTA4MDAKU3ViamVjdDogW1BBVENIXSBGaXggc29t ZSBjb25mdXNpb25zIGludm9sdmluZyBVbml2ZXJzYWwgVGltZSBhbmQgb2xkIHRpbWUKIHN0YW1w cy4KClRoZSBwcmV2aW91cyBzcGVjIHJlcXVpcmVkIFVUMSBmb3IgcHJlLVVUQyB0aW1lIHN0YW1w cywgYnV0IGluIHByYWN0aWNlClVUMiB3YXMgdGhlIGJhc2lzIG9mIGNpdmlsIHRpbWVrZWVwaW5n IGp1c3QgYmVmb3JlIFVUQyB3YXMgaW5hdWd1cmF0ZWQsCmFuZCBVVDAgaXMgYSBiZXR0ZXIgY2hv aWNlIHRoYW4gVVQxIGlmIHlvdSBnbyBiYWNrIGZhciBlbm91Z2guICBCdXQgdGhlCm1haW4gcG9p bnQgaXMgdGhhdCB0aGUgSFRNTCBzdGFuZGFyZCBzaG91bGRuJ3QgdHJ5IHRvIGltcG9zZSBhICJt dXN0Igp0aW1lIHN0YW5kYXJkIGhlcmUgKFVUMSB2cyBVVDIgdnMgd2hhdGV2ZXIpIHdoZW4gdGhp cyBkb2Vzbid0IGNvcnJlc3BvbmQKdG8gY29tbW9uIHByYWN0aWNlLiAgSW5zdGVhZCwgdGhlIHN0 YW5kYXJkIHNob3VsZCBzaW1wbHkgY2FsbCBvdXQKVW5pdmVyc2FsIFRpbWUgYXMgYSBnZW5lcmFs IHRlcm0uCgpTb21lIG90aGVyIG1pbm9yIGNoYW5nZXMgZm9yIHRoaXMgZWRpdDoKCiogQ2hhbmdl IGEgY291cGxlIG9mICJtdXN0InMgdG8gInNob3VsZCJzIHdoZW4gIm11c3QiIGlzIHRvbyBzdHJv bmcuCgoqIE1lbnRpb24gdGhhdCBVVCBpcyBtZWFuIHNvbGFyIHRpbWUsIG5vdCBzb2xhciB0aW1l LgoKKiBEb24ndCByZXF1aXJlIGFjdHVhbCBvYnNlcnZhdGlvbnMgYXQgR3JlZW53aWNoIGZvciBv bGQgdGltZSBzdGFtcHMgLS0KaWYgeW91IGdvIGJhY2sgZmFyIGVub3VnaCwgbm9ib2R5IHdhcyBh dCBHcmVlbndpY2ggdG8gb2JzZXJ2ZSBhbnl0aGluZy4KCk15IHNvdXJjZSBmb3IgVVQyIGJlaW5n IHRoZSBiYXNpcyBvZiBjaXZpbCB0aW1la2VlcGluZyBqdXN0IGJlZm9yZSBVVEMgaXMKdGhlIGZv bGxvd2luZyBlbWFpbCBmcm9tIFN0ZXZlIEFsbGVuIG9mIFVDTy9MaWNrIE9ic2VydmF0b3J5OgoK aHR0cDovL21tLmljYW5uLm9yZy9waXBlcm1haWwvdHovMjAxNC1Ob3ZlbWJlci8wMjE4NjcuaHRt bAoKSGUgY2l0ZXMgdGhlIEJ1bGxldGluIEhvcmFpcmUgb2YgdGhlIEJ1cmVhdSBJbnRlcm5hdGlv bmFsIGRlIGwnSGV1cmUsCk1hcmNoLUFwcmlsIDE5NjAsIHdoaWNoIGlzIGFyY2hpdmVkIGhlcmU6 CgpodHRwczovL3BsdXMuZ29vZ2xlLmNvbS9waG90b3MvMTEyMzIwMTM4NDgxMzc1MjM0NzY2L2Fs YnVtcy82MDc4MjI1NzMxMzUwMjI3MzYxCi0tLQogc291cmNlIHwgMTIgKysrKysrLS0tLS0tCiAx IGZpbGUgY2hhbmdlZCwgNiBpbnNlcnRpb25zKCspLCA2IGRlbGV0aW9ucygtKQoKZGlmZiAtLWdp dCBhL3NvdXJjZSBiL3NvdXJjZQppbmRleCA0OTU1ODhkLi5kZTY2YzhjIDEwMDY0NAotLS0gYS9z b3VyY2UKKysrIGIvc291cmNlCkBAIC00OTkxLDEyICs0OTkxLDEyIEBAIGlzIGNvbmZvcm1pbmcg ZGVwZW5kcyBvbiB3aGljaCBzcGVjcyBhcHBseSwgYW5kIGxlYXZlcyBpdCBhdCB0aGF0LiAtLT4K IAogICA8L29sPgogCi0gIDxwPlRpbWVzIGluIGRhdGVzIGJlZm9yZSB0aGUgZm9ybWF0aW9uIG9m IFVUQyBpbiB0aGUgbWlkIHR3ZW50aWV0aCBjZW50dXJ5IG11c3QgYmUgZXhwcmVzc2VkIGFuZAot ICBpbnRlcnByZXRlZCBpbiB0ZXJtcyBvZiBVVDEgKGNvbnRlbXBvcmFyeSBFYXJ0aCBzb2xhciB0 aW1lIGF0IHRoZSAwJmRlZzsgbG9uZ2l0dWRlKSwgbm90IFVUQyAodGhlCi0gIGFwcHJveGltYXRp b24gb2YgVVQxIHRoYXQgdGlja3MgaW4gU0kgc2Vjb25kcykuIFRpbWUgYmVmb3JlIHRoZSBmb3Jt YXRpb24gb2YgdGltZSB6b25lcyBtdXN0IGJlCi0gIGV4cHJlc3NlZCBhbmQgaW50ZXJwZXRlZCBh cyBVVDEgdGltZXMgd2l0aCBleHBsaWNpdCB0aW1lIHpvbmVzIHRoYXQgYXBwcm94aW1hdGUgdGhl IGNvbnRlbXBvcmFyeQotICBkaWZmZXJlbmNlIGJldHdlZW4gdGhlIGFwcHJvcHJpYXRlIGxvY2Fs IHRpbWUgYW5kIHRoZSB0aW1lIG9ic2VydmVkIGF0IHRoZSBsb2NhdGlvbiBvZiBHcmVlbndpY2gs Ci0gIExvbmRvbi48L3A+CisgIDxwPlRpbWVzIGluIGRhdGVzIGJlZm9yZSB0aGUgZm9ybWF0aW9u IG9mIFVUQyBpbiB0aGUgbWlkIHR3ZW50aWV0aCBjZW50dXJ5IHNob3VsZCBiZSBleHByZXNzZWQg YW5kCisgIGludGVycHJldGVkIGluIHRlcm1zIG9mIFVuaXZlcnNhbCBUaW1lIChjb250ZW1wb3Jh cnkgRWFydGggbWVhbiBzb2xhciB0aW1lIGF0IDAmZGVnOyBsb25naXR1ZGUKKyAgd2l0aCBkYXlz IHN0YXJ0aW5nIGF0IG1pZG5pZ2h0KSwgbm90IFVUQyAodGhlIHZlcnNpb24gb2YgVW5pdmVyc2Fs IFRpbWUgdGhhdCB0aWNrcyBpbiBTSQorICBzZWNvbmRzKS4gVGltZSBiZWZvcmUgdGhlIGZvcm1h dGlvbiBvZiB0aW1lIHpvbmVzIHNob3VsZCBiZSBleHByZXNzZWQgYW5kIGludGVycHJldGVkIGFz IFVuaXZlcnNhbAorICBUaW1lIHdpdGggZXhwbGljaXQgdGltZSB6b25lcyB0aGF0IGFwcHJveGlt YXRlIHRoZSBjb250ZW1wb3JhcnkgZGlmZmVyZW5jZSBiZXR3ZWVuIHRoZSBhcHByb3ByaWF0ZQor ICBsb2NhbCB0aW1lIGFuZCBVbml2ZXJzYWwgVGltZS48L3A+CiAKICAgPGRpdiBjbGFzcz0iZXhh bXBsZSI+CiAKLS0gCjEuOS4zCgo=