When Tails starts, the system time zone is set to GMT (Greenwich Mean Time). This time zone might be a few hours in the future if you are west of the United Kingdom, or in the past if you are east of the UK. The minutes should be accurate.

Time displayed with 'GMT' indication in top navigation bar

We do this for anonymity reasons: if some application reveals your actual time zone, it might help identifying who you are.

Having all Tails users set to the same time zone makes it more difficult to distinguish you amongst all the other Tails users.

Displaying the time in your local time zone

If connecting to Tor using a bridge fails and you have to set the clock and time zone of your computer, the time is displayed in your time zone instead of in GMT.

Time displayed without 'GMT' indication in top navigation bar

Fixing the clock when Tails fails to connect to Tor is currently the only way of changing the time zone of the time displayed in the top navigation bar.

In the future, we want to make it possible to change this time zone (#10819) from the desktop and store it in the Persistent Storage (#12094).

Time used by applications

Even if the time is displayed in your local time zone in the top navigation bar, the internal time used by all applications in Tails is still in GMT to protect your anonymity.

For example, the sending time of emails in Thunderbird or messages in Pidgin is always in GMT to avoid leaking your time zone to the people you write to.