Adobe Community: Message List - Bug handling XMP:DateTimeOriginal?

Re: Bug handling XMP:DateTimeOriginal?

forums_noreply@adobe.com — Sat, 11 Dec 2010 16:14:21 GMT

I see that this post is a few months old, but I wanted to add my support to opening up Time Zone info to the user. Many to most of my photos are taken in time zones other than my home, and over the years I have built up quite a collection of mis-timed photos. Some of my cameras allow this to be set internally, while others don't. It would help me greatly if there were a time zone field available to set them straight in post. If this gets implemented in LR4, please make sure to also create fields for 'Time (local)' and 'Time (absolute)' to use in the 'Rename' and 'Metadata search' options. Thanks.

Re: Bug handling XMP:DateTimeOriginal?

forums_noreply@adobe.com — Tue, 29 Jun 2010 07:31:04 GMT

Yes, perhaps the best solution would be to expose time zone information to the user and make it editable (at the expense of making things looking a bit more complicated to the end user).

I remember, Lightroom 1 was trying to mess around with time zones behind the scenes, and made more bad than good.

Re: Bug handling XMP:DateTimeOriginal?

forums_noreply@adobe.com — Mon, 28 Jun 2010 18:42:38 GMT

Lightroom should provide an option for displaying the time zone as stored in the XMP:DateTimeOriginal field, to remove ambiguity when working with programs and processes that use that field as defined in Adobe's XMP specification. For example, dates/times would display as 12/23/1957 8:14:38 PM -8:00.

Details:

After a little investigation, I see that LR ignores the time-zone indicator in the XMP:DateTimeOriginal field. For example, both of these DateTimeOriginal values:

1957:12:23 20:14:38-08:00

1957:12:23 20:14:38+00:00

display as "12/23/1957 8:14:38 PM". As another example, when sorting by increasing capture time, given these two photos:

a) 1957:12:23 20:00:00-08:00

b) 1957:12:23 19:00:00-10:00

LR will show photo b before photo a, even though b was taken after a in absolute time.

This is consistent and workable for users who only care about local time (just as the legacy EXIF:DateTimeOriginal field, which doesn't store time zones, has been workable).

My initial confusion arose because, in most other programs and non-computer contexts, when a time is displayed without a time zone, it is meant to be interpreted as local time relative to where the person is located. But that is not the case with LR -- when it shows the date/time stored in XMP:DateTimeOriginal, it silently drops the time zone, and the user can't assume that it is in local time.

It would be better for LR to provide an option for displaying the time zone stored in the XMP:DateTimeOriginal field. That would remove ambiguity for those who are integrating with other processes and programs that do pay attention to the absolute time a photo was taken and thus need to look at the time zone indicator. Here's a use case illustrating the ambiguity:

1. I set my camera clock to California time (-08:00).

2. I travel to London, neglect to change my camera's clock, and take a pic at noon, London time, on 1/30/2010. The pic's EXIF:DateTimeOriginal is set to 2010:01:30 04:00.

3. I import the pic into LR and see that it displays as 1/30/2010 4:00 AM.

4. I do Save Metadata, and see that XMP:DateTimeOriginal is set to 2010:01:30 04:00:00-08:00.

5. I use the Edit Capture Time > Shift By Set Number Of Hours (Time Zone Adjust) command to add an offset of +8 to the pic, which now shows in LR as 1/30/2010 12:00 PM.

6. I export the pic and send it off to a colleague in London.

7. The colleague's processes in London sees the XMP:DateTimeOriginal field as 2010:01:30 12:00:00-08:00 and incorrectly thinks the picture was taken at 12:00 California time (20:00 London time).

Adobe's XMP standard provides programs with the mechanism for avoiding ambiguity in times due to time zones, so it's unfortunate that LR doesn't take advantage of it.

Re: Bug handling XMP:DateTimeOriginal?

forums_noreply@adobe.com — Mon, 28 Jun 2010 07:50:26 GMT

What do you think Lightroom should do in this case? Rely on your system settings (that might not be correct)?

Bug handling XMP:DateTimeOriginal?

forums_noreply@adobe.com — Sun, 27 Jun 2010 05:22:55 GMT

It appears that LR 3 doesn't correctly interpret the "Z" format of the XMP:DateTimeOriginal metadata field -- it interprets it as local time rather than UTC.

To illustrate, using Exiftool, I set XMP:DateTimeOriginal of a photo to "1957:12:23 20:14:38-08:00", and after import LR correctly displays it as "12/23/1957 8:14:38 PM" (my local time zone is UTC-8). But if I set XMP:DateTimeOriginal to "1957:12:24 04:14:38Z", which the XMP standard says should be equivalent, LR shows it incorrectly as "12/24/1957 4:14:38 AM".

Is this a known bug? I see in older posts that LR 1 had lots of issues with date handling and time zones but LR 2 seemed to have fixed them? I have thousands of photos using the Z format, produced by Photoshop Elements 7 and 8.