Function dayOfIsoWeek
get the european dayOfWeek enumeration (Monday = 0 .. Sunday = 6)
Return the current day of a an isoWeek in european notation starting at at monday. The weekend includes saturday and sunday in Europe.
Param
data - either a Date, DateTime or any other type providing a 'dayOfWeek' property.
Returns
The isoWeek starting from 1 to 53
Note
DaysOfWeek starts at Sunday, not on Monday. This is a difference between european and anglo-american countries.