DST on R5

BobKnDP wrote:

koenkooi wrote:

Ali wrote:

Even if they could do it thru built in tables and without a network connection, I am sure companies don’t want to be in the business of having to release firmware updates for DST adjustments, which do happen pretty often around the world. Especially firmware updates many years after the camera has been released.

One problem with having a built in table that may go stale is that your camera will change the time when you are not expecting it.

Exactly this! If you look at https://www.iana.org/time-zones you can see that in 2022 there were at least 7 changes that caused a release of the tzdata files.

The example that comes to mind is Turkey in 2015, where they moved DST 2 weeks later, with little to no forewarning, for election shenanigans: https://www.bbc.com/news/world-europe-34631326

I hadn't considered the complexities of the world market.

However: do you change the time settings in your camera when you cross time zones?

Yes, I've gotten pretty good at remembering to do that right before boarding

Do you care if your EXIFs are tagged with the correct local time?

Extremely. But I care more that all cameras agree on which minute it is. Recent Canon cameras like to drift, my M6II does a few minutes per week. My R5 almost always has the GP-E2 mounted when used outdoors, so its clock is reasonably correct.

I wonder why the standard isn't set to Zulu time. As long as the camera's clock is set correctly with respect to that, the time tag would be accurate regardless of locale. (If memory serves, Microsoft Windows files are tagged by Zulu time. The time and date displayed in Windows are those of the PC's time zone, though.)

One of the issues is that the EXIF spec doesn't specify an option for Zulu/GMT nor for timezones. Canon does store the time offsets in a vendor specific section, so you can derive both the local time without adjustments, GMT and the time that is displayed on clocks locally.

Another thing to consider is how your photo organizer (e.g. LR) and viewer (e.g. phone) handle time. In the past I really liked how Google Photos would auto generate an album for your travels, including Indiana Jones style travel maps. The problem was that the generator would look at your current timezone, so if it ran after you got back home, your days would be off, in my case due to the 9 hours between California and The Netherlands. Google understands timezones, use GMT internally but use your current location to set midnight for showing the weekday.

I'd like to see a few changes to how Canon cameras handle time and syncing:

1. Allow time sync over bluetooth, currently the phone app only allows time sync over wifi. It does allow GPS sync over bluetooth...
2. Try contacting a time server every time a connection over wifi is made
3. Fix 'automatic sync' when using the phone app, it still needs a manual sync
4. Allow camera-to-camera time syncing over bluetooth, especially if one of them has GPS
5. Allow the app to update the timezone database so we can have automatic adjustment based on both time and position.