Suggested by Henrik Torsten Franzén – New
Many businesses still use weeks as their main planning format and when being forced to create custom fields with scripts populating these each time doesn't make sense. Having weeks as a stand function in D365 overall should already be a thing i hope it will be fairly soon as it shouldn't be that big a deal to implement in standard.
Sure there are different calendars but the correct calendar for the business is already chosen at creation of the environment.