The attached example workbook uses the sample data set Superstore to demonstrate all options. Sample workbook can be downloaded from the Attachments section on the right.

Option 1: Pivot the Date Fields

1. Pivot the date fields, so that there is only one field with date data, and a second field like "Event" that describes whether the event is "order placed" or "order shipped" Note: for some data sources, pivoting can be done directly in Tableau Desktop. For detailed directions, see Pivot Data from Columns to Rows
2. Right-click and drag [Pivot Field Values] to the Rows shelf
3. In the Drop Field dialog, select MY(Pivot Field Values) and click OK
4. Right-click [Pivot Field Names] in the data pane and select Aliases…
5. In the Edit Aliases dialog, give a more descriptive alias to Order Date and Ship Date and click OK
6. Drag [Pivot Field Names] to the Columns shelf
7. Right-click and drag [Order ID] to Text on the Marks card
8. In the Drop Field dialog, select CNTD(Order ID) and click OK

Option 2: Use an LOD Calculation

This option requires that every date field have at least one record for every date bin in the view. In this example, every row is a month, therefore both [Order Date] and [Ship Date] need to have at least one order for every month.

1. Choose one date field to create the date axis or headers. This example uses [Order Date]
2. Right-click and drag [Order Date] to the Rows shelf
3. In the Drop Field dialog, select MY(Order Date) with the blue # icon and click OK
4. Right-click and drag [Order ID] to Text on the Marks card
5. In the Drop Field dialog, select CNTD(Order ID)
6. Right-click the header "Distinct count of Order ID" in the view and select Edit Alias…
7. In the Edit Alias dialog, type in a new name and click OK
8. Create a calculated field with a name like "Orders Shipped" with a calculation similar to the following:
   
   MIN(
IF DATETRUNC('month', [Order Date]) = DATETRUNC('month', [Ship Date])
THEN { FIXED DATETRUNC('month', [Ship Date]) : COUNTD([Order ID]) }
END
)
   
   9. Double-click [Orders Shipped] in the data pane to add the field to the view
   
    

Option 3: Use Date Scaffolding

This option requires that one date field always come before another date field, and works best when the two dates fields are defining a range.

1. Create a table that contains a master list of all possible dates, which will be joined to the original data connection. In this example, that table is called "Master Date List"
2. Navigate to the Data source tab in Tableau Desktop
3. Add the "Sheet 1" table to the canvas area
4. In the Join dialog, so the following:
   1. Select Left
   2. Under Data Source, select Order Date
   3. Under Sheet 1, select Date
   4. Click the equal sign, and select <=
   5. Under Data Source, click Add new join clause, and select Ship Date
   6. Under Sheet 1, select Date
   7. Click the equal sign, and select >=
5. Select Analysis > Create Calculated Field
6. In the Calculated Field dialog box that opens, do the following, and then click OK:
   1. Name the calculated field. In this example, the calculated field is named "Orders Placed"
   2. In the formula field, create a calculation similar to the following:
      COUNTD(
IF DATETRUNC('month', [Order Date]) = DATETRUNC('month', [Date])
THEN [Order ID]
END
)
7. Create a calculated field with a name like "Orders Shipped" with a calculation similar to the following:
   COUNTD(
IF DATETRUNC('month', [Ship Date]) = DATETRUNC('month', [Date])
THEN [Order ID]
END
)
8. Right-click and drag [Date] to the Rows shelf
9. In the Drop Field dialog, select MY(Date) and click OK
10. Drag [Orders Placed] to Text on the Marks card
11. Double-click [Orders Shipped] in the data pane to add the field to the view

Option 4: Use Data Blending

This option will not work for a range of dates.

1. Create a table that contains a master list of all possible dates, and create a new connection to that list. In this example, that connection is called "Sheet1 (master date list)"
2. Navigate to Data > Sample - Superstore > Duplicate. In this example, I have named the two copies of "Sample - Superstore" as "Sample - Superstore (link on order date)" and "Sample - Superstore (link on ship date)" for clarity.
3. Navigate to Data > Edit Relationships…
4. In the Relationships dialog, do the following:
   1. For Primary data source, select Sheet1 (master date list)
   2. For secondary data source, select Sample - Superstore (link on order date)
   3. Select the Custom radio button
   4. click Add…
5. In the Add/Edit Field Mapping dialog, do the following:
   1. Click the arrow next to Date to expand the date options
   2. Select the date level that matches the most granular date level used in the view. In this example, the view uses MY(Date).
   3. In the right pane, click the arrow next to Order Date
   4. Select the matching date level for Order Date
   5. Click OK
6. Repeat steps 4-5 with "Sample - Superstore (link on ship date)" as the secondary data source, and adding a relationship on MY(Date) = MY(Ship Date)
7. Click OK to close the Relationships dialog
8. In a new worksheet, right-click and drag [Date] from the "Sheet1 (master date list)" data connection into the view
9. In the Drop Field dialog, select MY(Date) and click OK
10. Right-click the header "Distinct count of Order ID" in the view and select Edit Alias…
11. In the Edit Alias dialog, type in a more descriptive name and click OK
12. Right-click and drag [Order ID] from the "Sample - Superstore (link on order date)" data source onto Text on the Marks label
13. In the Drop Field dialog, select CNTD(Order ID) and click OK
14. Right-click and drag [Order ID] from the "Sample - Superstore (link on ship date)" data source onto Text on the Marks label
15. In the Drop Field dialog, select CNTD(Order ID) and click OK
16. Drag CNTD(Order ID) from Detail on the Marks card over the numbers in the view and drop the field
17. In the Edit Alias dialog, type in a more descriptive name and click OK