You can set date properties for a data source. To do so, right-click a data source in the Data window and choose Date Properties:
The options in the Date Properties dialog box are:
Week start - Specifies which day is considered the first day of the week. You can override the Week start value you set at the data source level by including a
start_of_weekvalue with certain date functions (
DATETRUNC). See Date Functions.
The initial value for this setting is in some cases determined by your data source. If the data source does not initialize the start-of-week day, then Tableau consults the system's locale settings.The day which is considered the first day of the week varies from region to region. For example, Sunday is the first day of the week in the US, while Monday is the first day in the EU.
This setting is disabled for cubes because this information is defined when cube designer creates the date/time dimension.After a data source is created, the Week start value does not automatically change if for any reason the default start-of-week setting changes in the host operating system (for example, if the data source is uploaded to Tableau Server in a different country). Calendar controls reflect the workbook locale rather than the data source's Week start setting. The exception is that a week trunc start of week that shows the week number in it will use the data source's Week start setting in order to provide a consistent week number value in the calendar.
Fiscal year start -
Specifies which month is considered the first month of the fiscal year.
To specify whether a date dimension uses the standard calendar (Jan. 1 -
Dec. 31) or the fiscal calendar, right-click the field in the Data window and select Default Properties > Calendar Type > and then select Standard Calendar or Fiscal Calendar.
For any date field in the view, you can then specify whether to use the
standard calendar or the fiscal calendar. For details, see Fiscal Dates.
Date format -
Specifies the default format for data dimensions, as displayed, for
example, in tooltips.To override the default date format for a date
dimension, right-click the field in the Data window and select Default Properties > Date Format > and then select one of the available formats.