Hello, I am using Debian Stretch with XFCE. I was customizing my clock, and encountered a few errors. I don't know what package in relation to this software cause this and I don't even know how to do bug report, so I am writing to you, instead to bug report e-mail address.
Basically, I right click on clock, then click on properties. Then on Clock Option, then I do custom format. But whenever I enter any one of those four options below, the entire clock display disappears. %N nanoseconds (000000000..999999999) %U week number of year, with Sunday as first day of week (00..53) %q quarter of year (1..4) %W week number of year, with Monday as first day of week (00..53) I am having the same problem with Xubuntu 18.04. Also, I did not have this problem when I was using Debian Jessie. Just wanted to let you know.