In Fedora 30, the xfce-4 panel 4.13.4 Orage clock/calendar app will not display the month or day in the right language or format. Rather than using the system language of US English, it uses Afar or Qafar, apparently a Cushitic language used in Ethiopia. I have found mentions of similar problems with language and format in Orage going back years. I have tried all sorts of things to fix the problem without success. Earlier, I was able to close Orage and start it again using a terminal and then it would temporarily show the clock and calendar correctly, but that stopped as soon as I closed the terminal-started instance of Orage. This is a significant problem, as it makes the calendar almost unusable and limits the clock options to digital formats, if you don't wish to learn Qafar.
The clock/calendar app is now working. At the command-line: timedatectl status showed non-English day names. I believe it was the command: localectl set-locale LANG=en_US.UTF-8 that finally got the day and month names in English and put Sunday first in the calendar.
The orage project is not maintained anymore and has been archived. Closing bugs.