I´m creating this idea to see if the community thinks that it will be useful.
Currently, using the CA Service Desk, when you pick in a date field it will pop up the calendar created with the date_chooser.js.
In this pop up the start day of the week is alwalys the Sunday ('Dom' in spanish, from Domingo).
If you want to customize this calendar there´s no out of the box possibility to do that, you cant change the start day of the week (from Sunday to Monday), the only possiblity is to customize the date_chooser.js file (and that is beyond scope of any support).
If you want to follow the ISO8601 (wich stablishes the international date format, and says that you have to fix the Monday as first day of the week) and use the gregorian calendar you can´t.
I think that it will be useful to create a parameter , maybe inside the Nx.env to fix the first day of the week for the date helpers.