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signalapp / libsignal

Home to the Signal Protocol as well as other cryptographic primitives which make Signal possible.
GNU Affero General Public License v3.0
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Incorrect timestamps from Mexico #522

Closed onchov closed 1 year ago

onchov commented 1 year ago

Not sure if this is the right place to log this bug, I'd normally go server but issues seem to be disabled there.

Description: Chatting with someone. My timezone is Central Europe (CEST = UTC+2), the other person is in Coahuila, Mexico (CST = UTC-6).

Actual results: My chat timestamps are correct. The other person's timestamps are one hour behind (ie when the timestamp for a message from me is "now", the timestamp for their message from the same time is "59m"; as time passes, my timestamps change correctly, ie "2m", "7m" etc, their timestamps change to indicate an hour behind).

Expected results: Timestamps from Mexico should display correctly.

Notes:

  1. All my devices affected, that includes Android and Desktop (Windows, Linux) versions of the Signal app.
  2. It may have something to do with the fact that parts of Mexico near the US border use daylight saving time while others don't? (see: https://en.wikipedia.org/wiki/Time_in_Mexico)
jrose-signal commented 1 year ago

Signal doesn't do anything special to timestamps, it just asks the OS what time it thinks it is. Our best guess is that their device has been set to the wrong time / time zone (perhaps they are deliberately adjusting their clock to work around the device applying DST when they don't want it to, or vice versa?).

You could ask them if other people they chat with in Signal see the same thing, or even to provide a debug log to compare their local timestamps with timestamps provided by the Signal servers.

(This isn't really the best place to file the issue either, since this repository only contains utility functions used by the client apps and the server. But since your best guess was that it was a server issue rather than a client issue it's understandable, so let's just continue here.)

onchov commented 1 year ago

Thank you, I'll try to get more info from the other party (I might be the only person they communicate through Signal with, though) and come back here with my findings.

onchov commented 1 year ago

OK, it wasn't a Signal issue, indeed. When both the time and time zone were provided by the cellular network, the user's time on the phone was incorrect so they manually changed it and that's why the -1 offset. The issue was corrected by letting the network provide the time again and changing the time zone instead. Thanks again and sorry for the noise.