Hi,
Thanks for your message. We see from your screen shot that you are not using a language plugin based on PO/MO files, you’re rather using a plugin that performs live translations.
The thing is that the 2-char version of the week-days is not included in the official PO/MO files of VikBooking. You are going to find just the 3-char version of the days of the week, like Sun, Mon, Tue etc.. In order to render the jQuery UI datepicker calendars, we get a portion of the 3-char strings by using a sub-string and by reading the first two multi-byte characters to support any kind of language. This is why your plugin is unable to translate those days of the week. In short, “Su” is not an existing PO/MO language definition, unlike the 3-char version “Sun”.
You should try to configure some exceptions in your multi-language plugin to manually translate the 2-char versions of the week days. This is the only case where a sub-string is used rather than the full translation string.
We hope this helps!
The VikWP Team