By default, data will be displayed by day, such as the order date or the invoice date. Often you will be more interested in period-specific data, however, such as the monthly turnover or the weekly production. For period-specific overviews, all sums and quantities for a specific period must be added up. The figure below shows the annual turnover by part group based on the posting date. Overviews like these will make it easy for you to compare the part group turnover data of several years.

1. In the pivot table, open the New fields tab.
2. Click Date fields.
3. In the Field name field, choose the date the period should be based on. For example, choose 'Posting date' if you want to total the turnover data for all posting dates falling in the period specified. You can make a selection from all available date fields in the preset.
4. In the Function field, select the period (such as 'Year') for which you want to display data.
5. In the New field name field, enter the name of the new field, if desired. If you do not enter a name, a name will be created automatically based on the values in the Field name and Function fields.
6. Click the Create button.

It is possible to perform calculations on fields containing numeric values, such as sums and quantities. The calculated values will be inserted into a new field. For example, if a form displays turnover and costs, but you would also like to see the margin, you can create a Margin field in the pivot table. The costs will then be deducted from the profit, and the result will be inserted into the new Margin field.

To add calculated data, follow these steps:

1. In the pivot table, open the New fields tab.
2. Click Calculated fields.
3. In the Field name field, select the field on which you want to perform a calculation. For example, select 'Turnover'.
4. In the Function field, select the calculation you want to perform. For instance, select '-' if you want the costs to be deducted from the turnover.
5. If you want to add a second field to the calculation, select the field in the Field name field. For example, select 'Costs' if you want the costs to be deducted from the turnover.
6. Instead of a second field, you can also add a fixed value to the calculation. If, for example, the calculated total time is expressed in seconds, you can convert that time into hours by dividing the total time by 3600. In that case, enter a fixed value of '3600'.
7. In the New field name field, enter the name of the new field, if desired. If you do not enter a name, a name will be created automatically.
8. Click the Create button.

To view the calculation performed in the field information, right-click the calculated field and choose 'Field information'.

To simplify the interpretation of the data in a pivot table, you can perform statistical calculations on fields containing numeric values, such as sums and quantities. The calculated values will be inserted into a new field.

1. In the pivot table, open the New fields tab.
2. Click Function fields.
3. In the Field name field, select the field on which you want to perform a statistical calculation. For example, select 'Turnover'.
4. In the Function field, select the statistical calculation you want to perform (see the table below).
5. If you selected 'Sum' in the Function field, you also need to fill in the Display field. You can choose to display the differences between columns, which can be absolute differences or percentage differences. Select 'None' if you do not require this information.

   When choosing percentage differences, you can also choose to display them in graphic form. Select the Graph check box to display the percentage as a bar.

6. In the New field name field, enter the name of the new field, if desired. If you do not enter a name, a name will be created automatically.
7. Click the Create button.

Statistical functions:

Statistical functions	Description
Quantity	Shows the number of lines that have been added up to return the value. For example, for the 2008 turnover sum, the values of 30 lines have been added up.
Total	Adds up numeric values in a row or column, and displays the total.
Min	Shows the lowest value in a row or column.
Max	Shows the highest value in a row or column.
Average	Shows the average of the values in a row or column.
StDef	Shows the standard deviation.
StDefP	Shows the standard deviation of the entire population.
Var	Shows the variance.
VarP	Shows the variance of the entire population.
Horizontal cumulative	Adds up the sums in a row, and displays the total sum.
Vertical cumulative	Adds up the sums in a column, and displays the total sum.

Display options for the Sum function:

Display options	Description
None	Apart from the summation, no other information is shown.
Absolute	Displays the differences between the columns. The value of the first column is deducted from the value of the next column. Value of column Y - Value of column X = Absolute difference.
Percent	Displays the percentage differences between the columns: (Value of column Y - Value of column X) / Value of column X * 100% = Percentage difference.
Percent of column	Displays the percentage differences between the columns: (Value of column Y - Value of column X) / Value of column X * 100% = Percentage difference.
Percent of row	Adds up the sums in a column, and displays the total sum.