On November 3rd, 2019, Daylights Savings Time (DST) was observed and caused issues with timestamps now being one hour off for GMT users.
As a result, users' mainly from Brazil have reported time stamps that are incorrect since Brazil does not observe DST this year.
The observance of the timestamp issue affects both Browser and Desktop clients of Discord.
In the meantime, the mobile application should be displaying properly.
This is currently under investigation with the Wizards of the Wumpii and they are working on fixing this up as soon as possible. However, there is no ETA on when the timestamps will return to standard time for those impacted.
We apologize for the inconvenience!