starting day of the week
all calendar date pickers should be customisable in terms of 1st day of the week according to a user preference or an organisation admin system setting (e.g. for region, time zone or account locale).

week number (CW##)
ideally, the corresponding week number should be displayed at the begining of each row of dates that belong in a given week to facilitate data input.

similarly, whenever feasible, the week number should be displayed next to certain date fields (e.g. expense date)
or allow for the CW field to be included in custom layouts for screens/ forms and/or pdf printouts (e.g. for expense reports, invoices etc.)

I am particularly interested in the ISO-8601 standard (i.e. weeks starting on Monday) for both date picker style and week numbering system, as an alternative to the American system currently in place.

Thank you