EXIF time stamps

Not for the first time I'm struggling to determine the times at which my
holiday photos in Italy were taken with my iPhone. (Neatness apart,
sometimes it matters, because it helps me to check times of walks/hikes
recorded with GPS. I use both walks and photos in making family holiday
videos/DVDs.)

The problem's of my own making and wouldn't have arisen if I'd applied
the simple expedient of taking occasional photos of my watch or nearby
clock.

This illustration of IrfanView windows hopefully states my questions
clearly:

https://www.dropbox.com/s/hcrzd9nxf9...ps-01.jpg?dl=0

Movies (MOV files from iPhone/iPad/Polaroid CUBE) are another matter; I
may be back...


Terry, East Grinstead, UK

Terry Pinnell wrote:

I'm struggling to determine the times at which my
holiday photos in Italy were taken with my iPhone.

This illustration of IrfanView windows hopefully states my questions
clearly:

https://www.dropbox.com/s/hcrzd9nxf9...ps-01.jpg?dl=0

Looks like an hour difference between meta-data datestamp and file
datestamp. Is one device set to use DST and the other not?

Meta-data is static. The device writes the meta-data at the time the
photo is taken and the meta-data stays that way no matter how time
thereafter changes on your phone. Copying a file would change its
timestamp in the file system but not alter any meta-data which is
contained within the file. Since the timestamps in the meta-data and
Irfanview are the same to the second, I'm guessing you removed a memory
card and slid it into a reader on your computer and that is where you
are using Irfanview to look at the file. That way you would not have
copied the file to change the timestamp. Could be your phone and
computer are set to use different DST offsets.

The phone likely locks in the current time regardless of where it is:
Italy, home, wherever. That won't change the meta-data in the file
recorded at the time of taking the photo. Don't know how your computer
is setup for DST or if it is even configured for the correct timezone.

On Thu, 8 Jun 2017 07:33:58 -0500, VanguardLH wrote:
Could be your phone and
computer are set to use different DST offsets.

Or one of them has outdated timezone information in the system.

Whisky-dave wrote:

On Thursday, 8 June 2017 10:21:06 UTC+1, Terry Pinnell wrote:
Not for the first time I'm struggling to determine the times at which my
holiday photos in Italy were taken with my iPhone. (Neatness apart,
sometimes it matters, because it helps me to check times of walks/hikes
recorded with GPS. I use both walks and photos in making family holiday
videos/DVDs.)

The problem's of my own making and wouldn't have arisen if I'd applied
the simple expedient of taking occasional photos of my watch or nearby
clock.

This illustration of IrfanView windows hopefully states my questions
clearly:

https://www.dropbox.com/s/hcrzd9nxf9...ps-01.jpg?dl=0

Movies (MOV files from iPhone/iPad/Polaroid CUBE) are another matter; I
may be back...


Terry, East Grinstead, UK

Were you set to GMT or BST when you were in italy, did you notice the file name also had this date/time info ?

As shown in my annotated screenshot, "Phone was showing correct local
time..." In Italy that is CEST, neither of the options you mention.

I've subsequently concluded that the answer to my first question ("Is
that always...") is Yes. (Assuming, of course, that iPhone/iPad has been
set, either manually or automatically, to the local time.)

That leaves my two other questions.

Terry, East Grinstead, UK

VanguardLH wrote:

Terry Pinnell wrote:

I'm struggling to determine the times at which my
holiday photos in Italy were taken with my iPhone.

This illustration of IrfanView windows hopefully states my questions
clearly:

https://www.dropbox.com/s/hcrzd9nxf9...ps-01.jpg?dl=0

Looks like an hour difference between meta-data datestamp and file
datestamp. Is one device set to use DST and the other not?

Meta-data is static. The device writes the meta-data at the time the
photo is taken and the meta-data stays that way no matter how time
thereafter changes on your phone. Copying a file would change its
timestamp in the file system but not alter any meta-data which is
contained within the file. Since the timestamps in the meta-data and
Irfanview are the same to the second, I'm guessing you removed a memory
card and slid it into a reader on your computer and that is where you
are using Irfanview to look at the file. That way you would not have
copied the file to change the timestamp. Could be your phone and
computer are set to use different DST offsets.

The phone likely locks in the current time regardless of where it is:
Italy, home, wherever. That won't change the meta-data in the file
recorded at the time of taking the photo. Don't know how your computer
is setup for DST or if it is even configured for the correct timezone.

Thanks both.

Time is set automatically on iPhone/iPad/Win 10 PC. (Settings General
Date and Time Set Automatically.)

The iOS devices were set correctly during my holiday in Italy as time
zone is automatically changed.

A photo take with the iPhone just now here in UK shows all four of those
dates are identical in a similar IrfanView screenshot. Note that it
automatically gets named 2017-06-09 10.03.38.jpg. I rename that (with a
macro, or in volume with Bulk Rename Utility) to the form
yyyymmdd-hhmmss. In this case 20170609-100338.jpg.

I'm still hazy as to why all my iPhone photos taken in Italy have that
IrfanView Properties date showing UK BST, while the EXIF window
correctly shows CEST. More coffee and I might get it...

Terry, East Grinstead, UK

Terry Pinnell wrote:

VanguardLH wrote:

Terry Pinnell wrote:

I'm struggling to determine the times at which my
holiday photos in Italy were taken with my iPhone.

This illustration of IrfanView windows hopefully states my questions
clearly:

https://www.dropbox.com/s/hcrzd9nxf9...ps-01.jpg?dl=0

Looks like an hour difference between meta-data datestamp and file
datestamp. Is one device set to use DST and the other not?

Meta-data is static. The device writes the meta-data at the time the
photo is taken and the meta-data stays that way no matter how time
thereafter changes on your phone. Copying a file would change its
timestamp in the file system but not alter any meta-data which is
contained within the file. Since the timestamps in the meta-data and
Irfanview are the same to the second, I'm guessing you removed a memory
card and slid it into a reader on your computer and that is where you
are using Irfanview to look at the file. That way you would not have
copied the file to change the timestamp. Could be your phone and
computer are set to use different DST offsets.

The phone likely locks in the current time regardless of where it is:
Italy, home, wherever. That won't change the meta-data in the file
recorded at the time of taking the photo. Don't know how your computer
is setup for DST or if it is even configured for the correct timezone.

Thanks both.

Time is set automatically on iPhone/iPad/Win 10 PC. (Settings General
Date and Time Set Automatically.)

The iOS devices were set correctly during my holiday in Italy as time
zone is automatically changed.

A photo take with the iPhone just now here in UK shows all four of those
dates are identical in a similar IrfanView screenshot. Note that it
automatically gets named 2017-06-09 10.03.38.jpg. I rename that (with a
macro, or in volume with Bulk Rename Utility) to the form
yyyymmdd-hhmmss. In this case 20170609-100338.jpg.

I'm still hazy as to why all my iPhone photos taken in Italy have that
IrfanView Properties date showing UK BST, while the EXIF window
correctly shows CEST. More coffee and I might get it...

Terry, East Grinstead, UK

But you are NOT running Irfanview on your phone. You are running it on
your computer. How did you get the photos from your phone to your
computer? Since the timestamp of the file is identical to the
timestamps in the meta-data but different by 1 hour, I suspect your
computer is looking at the timestamp on the file and biasing its
presentation in your file system per your regional time settings in your
computer.

When you were in Italy taking photos on your phone, did your phone
adjust for DST? Now that you're back home, is your phone showing the
correct local time or is it off by an hour? Is your home locale using
DST or not? What was the timezone for your phone at that you were in
Italy? What is the timezone for your home computer?

Don't know how you are getting the photo from your phone to your
computer. If you copied the file, it would get a new timestamp since it
is a new file. Did you move a memory card from phone to computer? If
so, if you put the card back in your phone, what does it show for the
file's timestamp?

On Fri, 9 Jun 2017 04:46:07 -0500, VanguardLH wrote:

But you are NOT running Irfanview on your phone. You are running it on
your computer. How did you get the photos from your phone to your
computer? Since the timestamp of the file is identical to the
timestamps in the meta-data but different by 1 hour, I suspect your
computer is looking at the timestamp on the file and biasing its
presentation in your file system per your regional time settings in your
computer.

NTFS buggers my timestamps by one hour when I'm in the
daylight saving period. I found a link he

https://support.microsoft.com/en-us/...ylight-savings

But can't read it, because of my hosts file. It probably
explains it.

[]'s
--
Don't be evil - Google 2004
We have a new policy - Google 2012

Shadow wrote:

On Fri, 9 Jun 2017 04:46:07 -0500, VanguardLH wrote:

But you are NOT running Irfanview on your phone. You are running it on
your computer. How did you get the photos from your phone to your
computer? Since the timestamp of the file is identical to the
timestamps in the meta-data but different by 1 hour, I suspect your
computer is looking at the timestamp on the file and biasing its
presentation in your file system per your regional time settings in your
computer.

NTFS buggers my timestamps by one hour when I'm in the
daylight saving period. I found a link he

https://support.microsoft.com/en-us/...ylight-savings

But can't read it, because of my hosts file. It probably
explains it.

[]'s

Thanks, interesting page, and a quirk I hadn't heard about.

However, at first sight I read it as arising only at clocks
forward/backward times?

But then I've never properly grasped the technical details behind the
various date/time fields in Windows: Modified, Accessed, Created, Taken
- and in Win 10 an apparently new (redundant?) one called 'Date'.

Unless perhaps the part about "... viewing another machine remotely
across one or more time zones through Event Viewer" also applies to
uploading files via Dropbox?

Terry, East Grinstead, UK

VanguardLH wrote:

Terry Pinnell wrote:

VanguardLH wrote:

Terry Pinnell wrote:

I'm struggling to determine the times at which my
holiday photos in Italy were taken with my iPhone.

This illustration of IrfanView windows hopefully states my questions
clearly:

https://www.dropbox.com/s/hcrzd9nxf9...ps-01.jpg?dl=0

Looks like an hour difference between meta-data datestamp and file
datestamp. Is one device set to use DST and the other not?

Meta-data is static. The device writes the meta-data at the time the
photo is taken and the meta-data stays that way no matter how time
thereafter changes on your phone. Copying a file would change its
timestamp in the file system but not alter any meta-data which is
contained within the file. Since the timestamps in the meta-data and
Irfanview are the same to the second, I'm guessing you removed a memory
card and slid it into a reader on your computer and that is where you
are using Irfanview to look at the file. That way you would not have
copied the file to change the timestamp. Could be your phone and
computer are set to use different DST offsets.

The phone likely locks in the current time regardless of where it is:
Italy, home, wherever. That won't change the meta-data in the file
recorded at the time of taking the photo. Don't know how your computer
is setup for DST or if it is even configured for the correct timezone.

Thanks both.

Time is set automatically on iPhone/iPad/Win 10 PC. (Settings General
Date and Time Set Automatically.)

The iOS devices were set correctly during my holiday in Italy as time
zone is automatically changed.

A photo take with the iPhone just now here in UK shows all four of those
dates are identical in a similar IrfanView screenshot. Note that it
automatically gets named 2017-06-09 10.03.38.jpg. I rename that (with a
macro, or in volume with Bulk Rename Utility) to the form
yyyymmdd-hhmmss. In this case 20170609-100338.jpg.

I'm still hazy as to why all my iPhone photos taken in Italy have that
IrfanView Properties date showing UK BST, while the EXIF window
correctly shows CEST. More coffee and I might get it...

Terry, East Grinstead, UK

But you are NOT running Irfanview on your phone. You are running it on
your computer. How did you get the photos from your phone to your
computer?

Uploaded to my PC via Dropbox.

Since the timestamp of the file is identical to the
timestamps in the meta-data but different by 1 hour, I suspect your
computer is looking at the timestamp on the file and biasing its
presentation in your file system per your regional time settings in your
computer.

Certainly sounds like you may be onto something, although I won't claim
to have got my head around it yet. And I'd have expected to see this
potential cause of confusion being discussed more widely, given the
number of iPhone/iPad users.

What's your view about the relevance of the article referenced by
Shadow?

When you were in Italy taking photos on your phone, did your phone
adjust for DST? Now that you're back home, is your phone showing the
correct local time or is it off by an hour? Is your home locale using
DST or not? What was the timezone for your phone at that you were in
Italy? What is the timezone for your home computer?


As I said in my previous post: "Time is set automatically on
iPhone/iPad/Win 10 PC," and "The iOS devices were set correctly during
my holiday in Italy as time zone is automatically changed."

So:
- Yes, it showed CEST (Central European Summer Time, GMT/UTC+0200)
- Yes, it shows correct time
- Yes, 'correct' obviously means BST
- (Again) CEST
- BST


Don't know how you are getting the photo from your phone to your
computer. If you copied the file, it would get a new timestamp since it
is a new file. Did you move a memory card from phone to computer? If
so, if you put the card back in your phone, what does it show for the
file's timestamp?

I answered that above.

Do you have a smartphone? It sounds not. Upload of photos from
smartphones (iOS, android, Windows) is a rather commonplace operation
these days. It's almost entirely done online, via wifi or 3G/4G.

Terry, East Grinstead, UK

On Fri, 09 Jun 2017 13:41:53 +0100, Terry Pinnell
wrote:

Shadow wrote:

On Fri, 9 Jun 2017 04:46:07 -0500, VanguardLH wrote:

But you are NOT running Irfanview on your phone. You are running it on
your computer. How did you get the photos from your phone to your
computer? Since the timestamp of the file is identical to the
timestamps in the meta-data but different by 1 hour, I suspect your
computer is looking at the timestamp on the file and biasing its
presentation in your file system per your regional time settings in your
computer.

NTFS buggers my timestamps by one hour when I'm in the
daylight saving period. I found a link he

https://support.microsoft.com/en-us/...ylight-savings

But can't read it, because of my hosts file. It probably
explains it.

[]'s

Thanks, interesting page, and a quirk I hadn't heard about.

However, at first sight I read it as arising only at clocks
forward/backward times?

But then I've never properly grasped the technical details behind the
various date/time fields in Windows: Modified, Accessed, Created, Taken
- and in Win 10 an apparently new (redundant?) one called 'Date'.

Unless perhaps the part about "... viewing another machine remotely
across one or more time zones through Event Viewer" also applies to
uploading files via Dropbox?

Like I said, I can't read the page. I don't keep any files "on
the web", and I don't use Win 10
This might help:

https://en.wikipedia.org/wiki/NTFS#Time

Unfortunately the reference
https://en.wikipedia.org/wiki/NTFS#cite_note-57

"Beating the Daylight Saving Time bug and getting correct file
modification times - The Code Project"
is dead
[]'s
--
Don't be evil - Google 2004
We have a new policy - Google 2012