Hey Kevin,
First of all, thanks for making Kimai! I love it and have been using it for several months. I just have a minor nitpick that you might be able to help me with.
In the calendar weekly view, my week, oddly enough, starts with Sunday. Essentially the last day of my week is Saturday and the first day is Sunday. I would like for the first day to be Monday and the last day Sunday. Could you point me in the right direction to make that happen?
Thank you for your time Kevin.
All the best,
Daniel

The first day of the week is based on the users locale (which is the language + optional country specific settings).
English is assumed to use Sunday as first day of the week. When you change the URL in your browser and replace /en/ with /de/ you'll see that in the German locale Monday is used as first day.
In which country are you located?
Are you an english native speaker or are you using English, because your language is not supported by Kimai?
Hey Kevin, thanks for the quick reply.
I'm based in Berlin, but want to use English as the UI language. How would I go about having Monday as the first day using English?
Not sure. Its impossible to configure the locale settings (like number formats, first day of the week) and language (translations) independently. Maybe if there is an english locale that uses Monday as first day of the week we could add that to Kimai.
I see. How are translation files stored? Maybe I could edit the English translation/locale file locally to start with Monday? Or is that not possible without recompiling?
Oh and if we need an English locale that has Monday as the first day, Ireland would do the trick. But how would the implementation of that look?
Question 1: Locale settings are international standardized and cannot be changed, they are fetched from a "globally shared database".
Question 2: Adding Ireland could do the trick.
See the documentation https://www.kimai.org/documentation/translations.html
Why not having a setting by user which can override the default first day from the locale?
This is what it looks like in Thunderbird with Lightning


I just started using Kimai today and being able to set the starting day of the week would be helpful. Our pay week runs from Friday to Thursday in order to give HR time to have the payroll ready Friday by noon.
You can configure the first day of the week (Monday or Sunday) now.
Fixed by #1952
Most helpful comment
Why not having a setting by user which can override the default first day from the locale?
This is what it looks like in
ThunderbirdwithLightning