Calculate the difference between two date picker controls in InfoPath using rules and formulas without coding

1. Design an InfoPath form template as shown in figure 1 with two Date Picker controls named  

    startDate and endDate, and one Text Box control named difference.

  

Figure 1. InfoPath form template in Design mode.

The Main data source of the InfoPath form template should resemble the following figure:

  

Figure 2. The Main data source of the InfoPath form template.

2. Add the following Rule to the startDate field:

Action: Set a field's value

Field: difference

Value:

(number(substring(../my:endDate, 9, 2)) + floor((153 * (number(substring(../my:endDate, 6, 2)) + 12 * (floor((14 - number(substring(../my:endDate, 6, 2))) div 12)) - 3) + 2) div 5) + (number(substring(../my:endDate, 1, 4)) + 4800 - (floor((14 - number(substring(../my:endDate, 6, 2))) div 12))) * 365 + floor((number(substring(../my:endDate, 1, 4)) + 4800 - (floor((14 - number(substring(../my:endDate, 6, 2))) div 12))) div 4) - floor((number(substring(../my:endDate, 1, 4)) + 4800 - (floor((14 - number(substring(../my:endDate, 6, 2))) div 12))) div 100) + floor((number(substring(../my:endDate, 1, 4)) + 4800 - (floor((14 - number(substring(../my:endDate, 6, 2))) div 12))) div 400) - 32045) - (number(substring(., 9, 2)) + floor((153 * (number(substring(., 6, 2)) + 12 * (floor((14 - number(substring(., 6, 2))) div 12)) - 3) + 2) div 5) + (number(substring(., 1, 4)) + 4800 - (floor((14 - number(substring(., 6, 2))) div 12))) * 365 + floor((number(substring(., 1, 4)) + 4800 - (floor((14 - number(substring(., 6, 2))) div 12))) div 4) - floor((number(substring(., 1, 4)) + 4800 - (floor((14 - number(substring(., 6, 2))) div 12))) div 100) + floor((number(substring(., 1, 4)) + 4800 - (floor((14 - number(substring(., 6, 2))) div 12))) div 400) - 32045)

with the following Conditions on the Rule:

startDate is not blank and

endDate is not blank

3. Add a second Rule to the startDate field with the following settings:

Action: Set a field's value

Field: difference

Value: 0

with the following Conditions on the Rule:

startDate is blank or

endDate is blank

4. Add the following Rule to the endDate field:

Action: Set a field's value

Field: difference

Value:

(number(substring(., 9, 2)) + floor((153 * (number(substring(., 6, 2)) + 12 * (floor((14 - number(substring(., 6, 2))) div 12)) - 3) + 2) div 5) + (number(substring(., 1, 4)) + 4800 - (floor((14 - number(substring(., 6, 2))) div 12))) * 365 + floor((number(substring(., 1, 4)) + 4800 - (floor((14 - number(substring(., 6, 2))) div 12))) div 4) - floor((number(substring(., 1, 4)) + 4800 - (floor((14 - number(substring(., 6, 2))) div 12))) div 100) + floor((number(substring(., 1, 4)) + 4800 - (floor((14 - number(substring(., 6, 2))) div 12))) div 400) - 32045) - (number(substring(../my:startDate, 9, 2)) + floor((153 * (number(substring(../my:startDate, 6, 2)) + 12 * (floor((14 - number(substring(../my:startDate, 6, 2))) div 12)) - 3) + 2) div 5) + (number(substring(../my:startDate, 1, 4)) + 4800 - (floor((14 - number(substring(../my:startDate, 6, 2))) div 12))) * 365 + floor((number(substring(../my:startDate, 1, 4)) + 4800 - (floor((14 - number(substring(../my:startDate, 6, 2))) div 12))) div 4) - floor((number(substring(../my:startDate, 1, 4)) + 4800 - (floor((14 - number(substring(../my:startDate, 6, 2))) div 12))) div 100) + floor((number(substring(../my:startDate, 1, 4)) + 4800 - (floor((14 - number(substring(../my:startDate, 6, 2))) div 12))) div 400) - 32045)

with the following Conditions on the Rule:

startDate is not blank and

endDate is not blank

5. Add a second Rule to the endDate field with the following settings:

Action: Set a field's value

Field: difference

Value: 0

with the following Conditions on the Rule:

startDate is blank or

endDate is blank

6. Add the following Rule to the difference field:

Action: Set a field's value

Field: .

Value: 0

with the following Condition on the Rule:

difference does not match pattern Custom Pattern: -{0,1}\d+

You should now have a fully functional InfoPath form that will calculate the difference between the dates soon after you have entered valid dates. This solution also works for InfoPath 2003 form templates and InfoPath 2007 browser-enabled form templates.