Set date based on EXIF does not work pre year 1970

[matti]

Hello, Why does the action "Set creation and modification date based on EXIF" not work with EXIF dates before year 1970? The dates of such files are incorrectly set +136 years. (GraphicConverter 8 build890 on 10.7.4). The "Set EXIF timestamp" command's "Set the file date to the EXIF date, too" fails similarly. I have some scanned slides from the 1950's and I have successfully set their EXIF dates as such with GC. Renaming based on EXIF works, too. But I'd also like to set the files' creation and modification dates to the 1950's. As a workaround, I now manually set them with FileBuddy. BTW, I set the file 1950 dates on OS X 10.6.8 but now 10.7.4 seems to have set those to 1970 behind my back anyway. I guess UNIX starts some dates from 1970 but there was life before that date, too! So is it possible to use such old files dates with GC or 10.7?? regards, - Matti

[matti]

Hello, So I can set old file dates such as year 1958 with FileBuddy in OS X 10.6.8. But after a reboot all those dates are reverted to blank in Finder file lists and FileBuddy shows them as year 1904. Is this a limitation of the file system?? Could GC handle this more gracefully? - Matti

[thorstenlemke]

Hello,the MacOS file system starts at 1970.Thorsten On 19.06.2012, at 19:07, Matti wrote:   Hello, Why does the action "Set creation and modification date based on EXIF" not work with EXIF dates before year 1970? The dates of such files are incorrectly set +136 years. (GraphicConverter 8 build890 on 10.7.4). The "Set EXIF timestamp" command's "Set the file date to the EXIF date, too" fails similarly. I have some scanned slides from the 1950's and I have successfully set their EXIF dates as such with GC. Renaming based on EXIF works, too. But I'd also like to set the files' creation and modification dates to the 1950's. As a workaround, I now manually set them with FileBuddy. BTW, I set the file 1950 dates on OS X 10.6.8 but now 10.7.4 seems to have set those to 1970 behind my back anyway. I guess UNIX starts some dates from 1970 but there was life before that date, too! So is it possible to use such old files dates with GC or 10.7?? regards, - Matti

[thorstenlemke]

Hello Matti,this is a limitation of the file system.Thorsten On 19.06.2012, at 19:35, Matti wrote:   Hello, So I can set old file dates such as year 1958 with FileBuddy in OS X 10.6.8. But after a reboot all those dates are reverted to blank in Finder file lists and FileBuddy shows them as year 1904. Is this a limitation of the file system?? Could GC handle this more gracefully? - Matti

[Wessel Jan]

Hi, The underlying system is UNIX. UNIX has the "touch" command. The touch utility sets the modification and access times of files. Used with the "t" option it can change the Access and Modification times to the specified time instead of the current time of day. The argument is of the form ``[[CC]YY]MMDDhhmm[.SS]' Note that with the "t" option you can thus also set the date. However, when trying this I found the following: - I can set the Finder Created date to an earlier date than the current one, but once set, I cannot set it back to a later date. - I can set the Finder Modified date to any date I like. (Probably FileBuddy uses this Touch command too) The "m" option changes the Finder Modified date/time to the current system date/time The "a" option does not change the Finder Created date, once I changed it with the "t" option to an earlier date. On my system(OSX 10.7.4) the "a" and "m" option set the time and date to the current system time and date. And,..... argh..., when rebooting the system both date/time are set to Jan 1 1970. Ahh, UNIX, it stores a date as the number of seconds elapsed since 1/1/1970. When we change to a date before that, the number becomes negative. And although Finder seems to be able to show that, upon reboot the system (UNIX ?) resets it to zero. So it's more a OSX problem I guess than a GC problem, or does someone know more about this? Jan Wessel Email adres : jhwessel@xs4all.nl On Jun 19, 2012, at 7:07 PM, Matti wrote: > Hello, > > Why does the action "Set creation and modification date based on EXIF" not work with EXIF dates before year 1970? The dates of such files are incorrectly set +136 years. (GraphicConverter 8 build890 on 10.7.4). > > The "Set EXIF timestamp" command's "Set the file date to the EXIF date, too" fails similarly. > > I have some scanned slides from the 1950's and I have successfully set their EXIF dates as such with GC. Renaming based on EXIF works, too. > > But I'd also like to set the files' creation and modification dates to the 1950's. As a workaround, I now manually set them with FileBuddy. > > BTW, I set the file 1950 dates on OS X 10.6.8 but now 10.7.4 seems to have set those to 1970 behind my back anyway. > > I guess UNIX starts some dates from 1970 but there was life before that date, too! > > So is it possible to use such old files dates with GC or 10.7?? > > regards, > > - Matti > > Jan Wessel Email adres : jhwessel@xs4all.nl

[matti]

OK, but why does GC set the file dates of such files with EXIF dates in the 1950's to year ~2090?? Shouldn't it just label them as 1970 (hopefully with the month-day-minute-second info intact)? > this is a limitation of the file system. > > Thorsten

[Wessel Jan]

Hmm, I tried some, indeed something strange going on. Will try and do some structured testing in the morning. Regards, Jan On Jun 20, 2012, at 12:09 AM, Matti wrote: > OK, but why does GC set the file dates of such files with EXIF dates in the 1950's to year ~2090?? Shouldn't it just label them as 1970 (hopefully with the month-day-minute-second info intact)? > > > this is a limitation of the file system. > > > > Thorsten > > Jan Wessel Email adres : jhwessel@xs4all.nl

[matti]

GC 6.7.6 sets the file date as 1.1.1970. And even that is then for some reason zeroed to just hyphens in file lists after a reboot (FileBuddy shows them as year 1904). On the other hand, GC 8 build890 sets the file date to the distant future! - Matti --- In gcmac@yahoogroups.com, "Matti" <matti.haveri@...> wrote: > > OK, but why does GC set the file dates of such files with EXIF dates in the 1950's to year ~2090?? Shouldn't it just label them as 1970 (hopefully with the month-day-minute-second info intact)? > > > this is a limitation of the file system. > > > > Thorsten >

[David L. Wasley]

My guess would be some ambiguity about signed versus unsigned integers used to represent "date/time" values.  If an unsigned 32 bit integer is used, then the latest date in can represent is Sun Feb  7 06:28:15 UTC 2106.  If a 32 bit signed integer is used, then the latest date becomes Tue Jan 19 03:14:07 UTC 2038 but it also can represent dates before 1/1/1970 as far back as Fri Dec 13 20:45:53 UTC 1901.By contrast, IBM software keeps date/time as microseconds since 1/1/1904 using a 64 bit integer.  I don't recall if it is signed or not.If software does math on date/time or does conversion back and forth, it needs to be consistent in using the same "type" of integer in all cases.In any case, archeologists or futurists will run into trouble unless they get software to keep date/times as strings. David On Jun 19, 2012, at 4:07 PM, Matti wrote:   GC 6.7.6 sets the file date as 1.1.1970. And even that is then for some reason zeroed to just hyphens in file lists after a reboot (FileBuddy shows them as year 1904). On the other hand, GC 8 build890 sets the file date to the distant future! - Matti --- In gcmac@yahoogroups.com, "Matti" <matti.haveri@...> wrote: > > OK, but why does GC set the file dates of such files with EXIF dates in the 1950's to year ~2090?? Shouldn't it just label them as 1970 (hopefully with the month-day-minute-second info intact)? > > > this is a limitation of the file system. > > > > Thorsten >

[Wessel Jan]

Hi, As promised some more structured testing. I must say, peculiar behavior. After restarting the system, Finder displays for testpic2 and testpic3 (dates before 1-1-19070) for all dates Thursday, January 1, 1970 1:00 AM Changing the EXIF date, changes the modification and creation date in Finder display, and sometimes the time Setting Creaiion and Modification date according to Exif, changes day and month but not the year, but also touches the time setting it seems. I hope Thorsten can find something. Running OSX 10.7.4 and GC version 8 (868) Thorsten let me know if you want me to run some more testing Original data for testpic1: Created Tuesday, January 10, 2012 9:23 PM Modified Tuesday, January 10, 2012 9:23 PM Last Opened Tuesday, January 10, 2012 9:23 PM 1. Using GC, Action, Date, Set File Date Setting to 1972 -> Finder displays: Created Monday, January 10, 1972 9:23 PM Modified Monday, January 10, 1972 9:23 PM Last Opened Monday, January 10, 1972 9:23 PM 2. Using GC, Action, Metadata, Set Exif date Setting to 1971 -> Finder displays: Created Monday, January 10, 1972 9:23 PM Modified Monday, January 10, 1972 9:23 PM Last Opened Monday, January 10, 1972 9:23 PM 3. Using GC, Action, Metadata, Ser Creation and Modification date according to Exif -> Finder displays: Created Wednesday, November 3, 1971 9:12 AM Modified Wednesday, November 3, 1971 9:12 AM Last Opened Wednesday, November 3, 1971 9:12 AM Original data for testpic2: Created Tuesday, January 10, 2012 9:06 PM Modified Tuesday, January 10, 2012 9:06 PM Last Opened Tuesday, January 10, 2012 9:06 PM 1. Using GC, Action, Date, Set File Date Setting to 1961 -> Finder displays: Created Tuesday, January 10, 1961 9:06 PM Modified Tuesday, January 10, 1961 9:06 PM Last Opened Tuesday, January 10, 1961 9:06 PM 2. Using GC, Action, Metadata, Set Exif date Setting to 1961 -> Finder displays: Created Saturday, February 16, 2097 3:34 AM Modified Saturday, February 16, 2097 3:34 AM Last Opened Saturday, February 16, 2097 3:34 AM 3. Using GC, Action, Metadata, Ser Creation and Modification date according to Exif -> Finder displays: Created Monday, December 9, 2097 5:17 PM Modified Monday, December 9, 2097 5:17 PM Last Opened Monday, December 9, 2097 5:17 PM Ok, lets try this again with another pic, tespic3 Original data for testpic3: Created Tuesday, January 10, 2012 9:23 PM Modified Tuesday, January 10, 2012 9:23 PM Last Opened Tuesday, January 10, 2012 9:23 PM 1. Using GC, Action, Date, Set File Date Setting to 1962 -> Finder displays: Created Wednesday, January 10, 1962 9:23 PM Modified Wednesday, January 10, 1962 9:23 PM Last Opened Wednesday, January 10, 1962 9:23 PM 2. Using GC, Action, Metadata, Set Exif date Setting to 1962 -> Finder displays: Created Sunday, February 16, 2098 3:51 AM Modified Sunday, February 16, 2098 3:51 AM Last Opened Sunday, February 16, 2098 3:51 AM 3. Using GC, Action, Metadata, Ser Creation and Modification date according to Exif -> Finder displays: Created Tuesday, December 9, 2098 4:29 PM Modified Tuesday, December 9, 2098 4:29 PM Last Opened Tuesday, December 9, 2098 4:29 PM On Jun 19, 2012, at 7:38 PM, Thorsten Lemke wrote: > Hello Matti, > > > this is a limitation of the file system. > > Thorsten > > > On 19.06.2012, at 19:35, Matti wrote: > >> >> Hello, >> >> So I can set old file dates such as year 1958 with FileBuddy in OS X 10.6.8. But after a reboot all those dates are reverted to blank in Finder file lists and FileBuddy shows them as year 1904. >> >> Is this a limitation of the file system?? Could GC handle this more gracefully? >> >> - Matti >> > > > Jan Wessel Email adres : jhwessel@xs4all.nl