My date defaulted to 'Sunday' and I need to change mine but it's grayed out as well.
This is the link which helps you in changing the start week day Changing Week Numbers | Tableau Software
But this will not work sometimes & explanation is here http://onlinehelp.tableausoftware.com/current/pro/online/en-us/help.htm#date_properties.html
Alternate solution of this problem is Setting the First Day of the Week to Monday | Tableau Software
Hope this may help!!!
Once you create an extract, in order to change the Start of Week, you must do the following:
- Right click the extract and select Remove to remove the extract and return to a live connection.
- Right click the live data connection and select Date Properties.
- Change the Start of Week day.
- Create the extract again.
Here is a link to another relevant thread: http://community.tableau.com/thread/136063