Author Topic: Daylight Saving Time  (Read 12563 times)

Offline wazrob

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Daylight Saving Time
« on: February 13, 2013, 01:50:59 AM »
My computer time zone is (UTC+10:00) Canberra, Melbourne, Sydney with DST in effect.  The actual time zone offset is (UTC +11:00).  When I ingest photos into Photo Mechanic it gives all photos the time zone of +10:00.  As my all GPX tracks uses UTC my photos are placed one hour off the correct position.  Is there any way that Photo Mechanic can take the DST time into effect and update the correct UTC offsett into my photos.  If the computer says UTC+10:00 and DST is in effect then upload the photos as UTC+11:00.  I currently have to use ExifTool to add 1:00 hour to my photos.  In May I am going on a world cruise and will therefore go through 24 time zones, some with + DST some with no DST and some with - DST.  It would assist if Photo Mechanic loaded the correct time zone offset and I do not have to add or subtract 1:00 hour from some of my photos.

Offline Sven

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Re: Daylight Saving Time
« Reply #1 on: February 13, 2013, 03:45:50 AM »
Hi!

What about adjusting the time in the camera itself to reflect the current time(zone)?

Sven
Changed from behind the cam to one who buys images as I started to run. No cam or lens left.

Offline Hayo Baan

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Re: Daylight Saving Time
« Reply #2 on: February 13, 2013, 03:50:39 AM »
What about adjusting the time in the camera itself to reflect the current time(zone)?

Setting the correct time in-camera is the best solution, of course. However, for your already shot images, you can use PM's adjust time from the tools menu.

Hope this helps,
Hayo
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Offline wazrob

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Re: Daylight Saving Time
« Reply #3 on: February 13, 2013, 04:26:41 PM »
The time on my laptop and my camera is correct for the time zone that i am visiting.

I ingest with Photo Mechanic on a daily basis, this adds an XMP and IPTC date and time with a time zone offset, this offset is the offset of the laptop without taking DST into consideration.
For example it generates 2013:01:07 07:42:43-04:00 it should generate 2013:01:07 07:42:43-03:00 as DST is in force.

I therefore cannot geotag the photos with my Garmin GPS track until i use ExifTool to add 1:00 to the time zone offset.

What i am asking is can Photo Mechanic add the correct time zone offset to the XMP and IPTC date and time that they generate.

Thanks,
Warren

Offline Kirk Baker

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Re: Daylight Saving Time
« Reply #4 on: February 13, 2013, 05:04:17 PM »
Warren,

The time on my laptop and my camera is correct for the time zone that i am visiting.

I ingest with Photo Mechanic on a daily basis, this adds an XMP and IPTC date and time with a time zone offset, this offset is the offset of the laptop without taking DST into consideration.
For example it generates 2013:01:07 07:42:43-04:00 it should generate 2013:01:07 07:42:43-03:00 as DST is in force.

I therefore cannot geotag the photos with my Garmin GPS track until i use ExifTool to add 1:00 to the time zone offset.

What i am asking is can Photo Mechanic add the correct time zone offset to the XMP and IPTC date and time that they generate.

It could in all likelihood be changed to take DST into account.  But until it does, you can use the tool that Hayo recommended that is built into PM instead of using ExifTool.  It is called "Adjust Capture Dates and Times and it is on the Tools menu in Photo Mechanic.  It is very easy to adjust the time by an hour or by minutes or whatever you need.

-Kirk

Offline wazrob

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Re: Daylight Saving Time
« Reply #5 on: February 13, 2013, 09:07:14 PM »
I don't need to change the time, i need to change the time zone offset.  Or are you saying that i should put the wrong time on my photos?

As Photo Mechanic is creating this data i would hope that Photo Mechanic create the correct data, not incorrect data.

Thanks,
Warren

Offline wazrob

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Re: Daylight Saving Time
« Reply #6 on: February 14, 2013, 01:49:58 AM »
Kirk,

I know that the catalog feature is your major concern, to me correct data is more important.

If you are adding meta data to a photo, add the correct data or do not add the data at all.  No data is better than data in error.

Thanks,
Warren

Offline Kirk Baker

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Re: Daylight Saving Time
« Reply #7 on: February 14, 2013, 06:29:26 AM »
Warren,

I know that the catalog feature is your major concern, to me correct data is more important.

If you are adding meta data to a photo, add the correct data or do not add the data at all.  No data is better than data in error.

Your concerns are noted.  Please read this post and answer as many of the questions as you can: http://forums.camerabits.com/index.php?topic=4688.0

-Kirk
« Last Edit: February 14, 2013, 06:32:40 AM by Kirk Baker »

Offline wazrob

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Re: Daylight Saving Time
« Reply #8 on: February 14, 2013, 03:15:52 PM »
Kirk,

I am running Photo Mechanic version 5, build 13644 (f7494941) on Windows 7x64.

I have attached a screen shot of my computers time zone plus a screen shot of the XMP data after i ingested with Photo Mechanic.  From this you can see that it was ingested with a time zone offset of +10, it should be +11.

You say that my concerns are noted, i hope that the error will be corrected soon.

Thanks,
Warren

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Offline Kirk Baker

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Re: Daylight Saving Time
« Reply #9 on: February 14, 2013, 03:58:13 PM »
Warren,

I am running Photo Mechanic version 5, build 13644 (f7494941) on Windows 7x64.

I have attached a screen shot of my computers time zone plus a screen shot of the XMP data after i ingested with Photo Mechanic.  From this you can see that it was ingested with a time zone offset of +10, it should be +11.

You say that my concerns are noted, i hope that the error will be corrected soon.

Indeed I did.  We really don't need any further encouragement.  If you like, I'll get you an updated build when it is ready.

-Kirk

Offline Bob M

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Re: Daylight Saving Time
« Reply #10 on: February 20, 2013, 04:55:15 PM »
I followed this thread with interest but did not jump in in case I did not properly understand the issue.  However, I am posting now because I note in your announcement of build 13764, that you say that PM will now use Daylight Savings Time to adjust GMT offsets.  Hopefully the user will have the option of turning this "feature" off.

My cameras do not understand daylight savings time;  Consequently I leave the time and date set to EST (GMT-5), 365 days a year.  My capture time is always expressed as GMT-5.  My GPX files always express the time as GMT.  When I wish to import GPS coordinates, my GMT offset is always -5 hours, regardless of whether it is winter or summer.  If PM now adjusts my capture time offset on the assumption that DST is in effect and that consequently my camera time is expressed in DST, then you will be breaking my workflow and introducing time errors into my metadata.


Offline Kirk Baker

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Re: Daylight Saving Time
« Reply #11 on: February 20, 2013, 06:08:16 PM »
I followed this thread with interest but did not jump in in case I did not properly understand the issue.  However, I am posting now because I note in your announcement of build 13764, that you say that PM will now use Daylight Savings Time to adjust GMT offsets.  Hopefully the user will have the option of turning this "feature" off.

My cameras do not understand daylight savings time;  Consequently I leave the time and date set to EST (GMT-5), 365 days a year.  My capture time is always expressed as GMT-5.  My GPX files always express the time as GMT.  When I wish to import GPS coordinates, my GMT offset is always -5 hours, regardless of whether it is winter or summer.  If PM now adjusts my capture time offset on the assumption that DST is in effect and that consequently my camera time is expressed in DST, then you will be breaking my workflow and introducing time errors into my metadata.

OK, well then we can make it a preference in the next build.  I do wish you had mentioned your concerns when you had them.  Please feel free to express your concerns on these forums.  They're very much welcomed.

-Kirk

Offline Hayo Baan

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Re: Daylight Saving Time
« Reply #12 on: February 20, 2013, 10:08:01 PM »
I'm a bit confused now as to what this fix actually does.

Kirk, are you saying you are magically applying a DST offset, even when the camera isn't set to (or does not support) DST? That would be weird. But I guess I am misunderstanding things here?

(Heck, I have taken shots forgetting to turn on DST, and then used the adjust capture times tool in PM to correct the time of the shot. If PM would now magically apply DST again, times will be incorrect.

Oh, and to make matters worse, not all countries have DST, nor do they have it at the same dates…

Confused  :o
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Offline Kirk Baker

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Re: Daylight Saving Time
« Reply #13 on: February 21, 2013, 06:47:32 AM »
I'm a bit confused now as to what this fix actually does.

Kirk, are you saying you are magically applying a DST offset, even when the camera isn't set to (or does not support) DST? That would be weird. But I guess I am misunderstanding things here?

(Heck, I have taken shots forgetting to turn on DST, and then used the adjust capture times tool in PM to correct the time of the shot. If PM would now magically apply DST again, times will be incorrect.

Oh, and to make matters worse, not all countries have DST, nor do they have it at the same dates…

Confused  :o

Cameras (really the EXIF Capture Time tag) has no provision for GMT Offset at all.  The computer's GMT Offset is always used from the host computer.  This much has always been true in Photo Mechanic (at least as long as I can remember.)

DST is enabled/disabled on the host computer.  In countries (or states/provinces) that don't observe DST, the DST offset would always be zero.  I know for certain that Mac OS X can automatically determine when to apply DST but I don't know if Windows does offhand.  PM 5 is now asking the computer: Is DST in effect now?  If it returns NO then the GMT Offset is not modified.  It shouldn't matter which day a particular country/county/state/province enables it as long as it is observed consistently on your computer system.

If this turns out to be an actual issue for you all, we'll be sure to make a preference in an update build to make it off by default and folks like Warren can turn it back on.

-Kirk

Offline Hayo Baan

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Re: Daylight Saving Time
« Reply #14 on: February 22, 2013, 04:33:57 AM »
Cameras (really the EXIF Capture Time tag) has no provision for GMT Offset at all.  The computer's GMT Offset is always used from the host computer.  This much has always been true in Photo Mechanic (at least as long as I can remember.)

DST is enabled/disabled on the host computer.  In countries (or states/provinces) that don't observe DST, the DST offset would always be zero.  I know for certain that Mac OS X can automatically determine when to apply DST but I don't know if Windows does offhand.  PM 5 is now asking the computer: Is DST in effect now?  If it returns NO then the GMT Offset is not modified.  It shouldn't matter which day a particular country/county/state/province enables it as long as it is observed consistently on your computer system.

If this turns out to be an actual issue for you all, we'll be sure to make a preference in an update build to make it off by default and folks like Warren can turn it back on.

Hi Kirk, I'm still a bit confused. What does this fix actually change? if I look at the exif data, I do see times with e.g., +09:00 (which is correct as they were taken in Japan) or +01:00 (which is my own time zone). I guess, with daylight savings in effect at the time the shot was taken the times should actually read +10:00 and +2:00? Is this what your fix does?

As a side note: I found my newer cameras do actually record both the DST flag as well as the timezone (as e.g.,+ 09:00), older camera's only register the timezone, or nothing of this sort at all.
I think, ideally, PM should be able to adjust these fields in the Adjust Capture Times in the tool menu. This way you can correct mistakes properly (forgotten to set DST, or change the timezone).
Hayo Baan - Photography
Web: www.hayobaan.nl