[PROPOSED] New edition of Calendrical Calculations
* theory.html (Calendrical issues): Update Reingold & Dershowitz citation to 4th edition. --- theory.html | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/theory.html b/theory.html index 4d8726d..596b32c 100644 --- a/theory.html +++ b/theory.html @@ -1155,10 +1155,10 @@ based on guesswork and these guesses may be corrected or improved. Calendrical issues are a bit out of scope for a time zone database, but they indicate the sort of problems that we would run into if we extended the time zone database further into the past. -An excellent resource in this area is Nachum Dershowitz and Edward M. -Reingold, <cite><a -href="https://www.cs.tau.ac.il/~nachum/calendar-book/third-edition/">Calendrical -Calculations: Third Edition</a></cite>, Cambridge University Press (2008). +An excellent resource in this area is Edward M. Reingold +and Nachum Dershowitz, <cite><a +href="https://www.cambridge.org/fr/academic/subjects/computer-science/computing-general-interest/calendrical-calculations-ultimate-edition-4th-edition">Calendrical +Calculations: The Ultimate Edition</a></cite>, Cambridge University Press (2018). Other information and sources are given in the file '<code>calendars</code>' in the <code><abbr>tz</abbr></code> distribution. They sometimes disagree. -- 2.7.4
Nice to see a new edition, but sadly the same use restrictions still apply, to quote: "The Functions (code, formulas, and calendar data) contained in this book and/or provided on the publisher’s web site for this book were written by Nachum Der- showitz and Edward M. Reingold (the “Authors”), who retain all rights to them except as granted in the License and subject to the warranty and liability limitations below. These Functions are subject to this book’s copyright. In case there is cause for doubt about whether a use you contemplate is authorized, please contact the Authors. 1. LICENSE. The Authors grant you a license for personal use. This means that for strictly personal use you may copy and use the code and keep a backup or archival copy also. The Authors grant you a license for re-use within non-commercial, non-profit software provided prominent credit is given and the Authors’ rights are preserved. Any other uses, including, without limitation, allowing the code or its output to be accessed, used, or available to others, are not permitted." Basically means I've never been able to read it for fear of taint... John. On 3 April 2018 at 06:25, Paul Eggert <eggert@cs.ucla.edu> wrote:
* theory.html (Calendrical issues): Update Reingold & Dershowitz citation to 4th edition. --- theory.html | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/theory.html b/theory.html index 4d8726d..596b32c 100644 --- a/theory.html +++ b/theory.html @@ -1155,10 +1155,10 @@ based on guesswork and these guesses may be corrected or improved. Calendrical issues are a bit out of scope for a time zone database, but they indicate the sort of problems that we would run into if we extended the time zone database further into the past. -An excellent resource in this area is Nachum Dershowitz and Edward M. -Reingold, <cite><a -href="https://www.cs.tau.ac.il/~nachum/calendar-book/third-edition/">Calendrical -Calculations: Third Edition</a></cite>, Cambridge University Press (2008). +An excellent resource in this area is Edward M. Reingold +and Nachum Dershowitz, <cite><a +href="https://www.cambridge.org/fr/academic/subjects/computer-science/computing-general-interest/calendrical-calculations-ultimate-edition-4th-edition">Calendrical +Calculations: The Ultimate Edition</a></cite>, Cambridge University Press (2018). Other information and sources are given in the file '<code>calendars</code>' in the <code><abbr>tz</abbr></code> distribution. They sometimes disagree. -- 2.7.4
On 2018-04-03 10:34, John Layt wrote:
On 3 April 2018 at 06:25, Paul Eggert wrote:
* theory.html (Calendrical issues): Update Reingold & Dershowitz citation to 4th edition. --- theory.html | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/theory.html b/theory.html index 4d8726d..596b32c 100644 --- a/theory.html +++ b/theory.html @@ -1155,10 +1155,10 @@ based on guesswork and these guesses may be corrected or improved. Calendrical issues are a bit out of scope for a time zone database, but they indicate the sort of problems that we would run into if we extended the time zone database further into the past. -An excellent resource in this area is Nachum Dershowitz and Edward M. -Reingold, <cite><a -href="https://www.cs.tau.ac.il/~nachum/calendar-book/third-edition/">Calendrical -Calculations: Third Edition</a></cite>, Cambridge University Press (2008). +An excellent resource in this area is Edward M. Reingold +and Nachum Dershowitz, <cite><a +href="https://www.cambridge.org/fr/academic/subjects/computer-science/computing-general-interest/calendrical-calculations-ultimate-edition-4th-edition">Calendrical +Calculations: The Ultimate Edition</a></cite>, Cambridge University Press (2018). Other information and sources are given in the file '<code>calendars</code>' in the <code><abbr>tz</abbr></code> distribution. They sometimes disagree.
Nice to see a new edition, but sadly the same use restrictions still apply, to quote:> "The Functions (code, formulas, and calendar data) contained in this book and/or provided on the publisher’s web site for this book were written by Nachum Dershowitz and Edward M. Reingold (the “Authors”), who retain all rights to them except as granted in the License and subject to the warranty and liability limitations below. These Functions are subject to this book’s copyright.> In case there is cause for doubt about whether a use you contemplate is authorized, please contact the Authors.> 1. LICENSE. The Authors grant you a license for personal use. This means that for strictly personal use you may copy and use the code and keep a backup or archival copy also. The Authors grant you a license for re-use within non-commercial, non-profit software provided prominent credit is given and the Authors’ rights are preserved. Any other uses, including, without limitation, allowing the code or its output to be accessed, used, or available to others, are not permitted."> Basically means I've never been able to read it for fear of taint... Erlang port published with same licence terms:
https://github.com/ferd/calcalc I doubt any issues with ports, as long as you don't publish the original Lisp, which is pretty straightforward code (except for the need to express formulae as Lisp expressions), or the output from the Lisp. Many of the formulae are obvious, published in their own earlier or others' works, or other public calendar software e.g. tzcode. Uses of non-creative non-original common public factual data and mathematical formulae (essential to all uses of calendars), including information from reverse engineering, appear to be unrestricted, from what I gather (IANAL). Why do you have a concern regarding taint? -- Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada
On Apr 3, 2018, at 2:50 PM, Brian Inglis <Brian.Inglis@SystematicSw.ab.ca> wrote:
... Many of the formulae are obvious, published in their own earlier or others' works, or other public calendar software e.g. tzcode. Uses of non-creative non-original common public factual data and mathematical formulae (essential to all uses of calendars), including information from reverse engineering, appear to be unrestricted, from what I gather (IANAL).
I know the "facts aren't copyrightable" rule in the USA, but copyright laws vary among countries. paul
On 3 April 2018 at 19:50, Brian Inglis <Brian.Inglis@systematicsw.ab.ca> wrote:
I doubt any issues with ports, as long as you don't publish the original Lisp, which is pretty straightforward code (except for the need to express formulae as Lisp expressions), or the output from the Lisp. Many of the formulae are obvious, published in their own earlier or others' works, or other public calendar software e.g. tzcode. Uses of non-creative non-original common public factual data and mathematical formulae (essential to all uses of calendars), including information from reverse engineering, appear to be unrestricted, from what I gather (IANAL).
Why do you have a concern regarding taint?
Mainly because I've contributed code to a dual-licensed GPL/commercial library that cannot accept code with non-commercial restrictions, but also due to past statements they've made and their own commercial licensing of the code and algorithms. I have no wish to become a test case in the remote and expensive American legal system :-) I fully agree that legally speaking their work probably is effectively public domain and free for use (or at least should be, your legal system may vary). As much as I disagree with their approach, I respect their wish to not share their work, it just means I've had to rely on more primary sources and my own deductions. John.
On 2018-04-03 13:39, John Layt wrote:
On 3 April 2018 at 19:50, Brian Inglis <Brian.Inglis@systematicsw.ab.ca> wrote:
I doubt any issues with ports, as long as you don't publish the original Lisp, which is pretty straightforward code (except for the need to express formulae as Lisp expressions), or the output from the Lisp. Many of the formulae are obvious, published in their own earlier or others' works, or other public calendar software e.g. tzcode. Uses of non-creative non-original common public factual data and mathematical formulae (essential to all uses of calendars), including information from reverse engineering, appear to be unrestricted, from what I gather (IANAL).
Why do you have a concern regarding taint?
Mainly because I've contributed code to a dual-licensed GPL/commercial library that cannot accept code with non-commercial restrictions, but also due to past statements they've made and their own commercial licensing of the code and algorithms. I have no wish to become a test case in the remote and expensive American legal system :-)
I find it hard to believe their exteremely slow CL code has much commercial value. Algorithms seem to be consistently treated as mathematical formulae, and I doubt any countries (even the Vatican!) have claims on basic calendar facts, as that makes calendars unusable.
I fully agree that legally speaking their work probably is effectively public domain and free for use (or at least should be, your legal system may vary). As much as I disagree with their approach, I respect their wish to not share their work, it just means I've had to rely on more primary sources and my own deductions.
Very much not public domain, as R&D claim a copyright on their book, code, and its output, and provide a licence for some other NC reuses, reserving copying or sharing their expression. As researchers, they may prefer their work be shared widely, but CUP do imply the book is useless, except as a book to read. This group discussed a lot of these issues around the lawsuit, and around the possible use of the canonical IERS leap-seconds.list rather than the currently distributed NIST file. -- Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada
On 04/03/2018 09:34 AM, John Layt wrote:
I've never been able to read it for fear of taint...
We do have to be quite careful about respecting copyright, for obvious reasons. However, I've read and used the ideas from the part of the book that does not include Lisp code, which is fine. Although the code is the heart of the book, all I want is its brain. Amusingly enough, the book's latest edition has a small time-zone section that cites Shanks but not tzdb. Perhaps I should file a bug report....
participants (4)
-
Brian Inglis -
John Layt -
Paul Eggert -
Paul.Koning＠dell.com