**UPDATE:** Due to the number of requests for adding more columns to this sample, I have re-designed the sample. If I have time in the future I will update the steps to create this new design; however, for now you can download the updated design here to see the changes. The expressions are very similar to the original design but I now use a repeating table for entering "break" times so you can have as many as you need!

How many times have you needed to calculate the difference between time entries…only to find out the only way to accomplish this was to write custom code? Well no more! If your time entries will not cross days, then you can use a number of functions and expressions to parse the entered times and calculate the difference. In the sample below we will show you the types of expressions that are needed for these calculations to work – I would encourage you to first create this sample as documented as the expressions are not for the “faint of heart!” :-)

**Note:** if you choose to copy/paste the expressions for this sample, you will use the Default Value box for each field and after clicking the “fx” button, be sure to also enable the “Exit XPath” option before you paste these expressions.

If you'd like to take a look at the completed version of this sample, here is the .xsn file - make sure to save it locally before opening it.

__Create the data structure__

1) Add a Repeating Table to your View with 4 columns

2) Rename the fields and specify the data types as follows, from left to right:

Name |
Data Type |

myDate | Date (date), Format: *3/14/2001 |

StartTime | Time (time), Format: *9:46 AM |

EndTime | Time (time), Format: *9:46 AM |

ActualTime | Text (string) |

3) Change the first field in the table to a Date Picker control

4) Add 2 additional fields to the Repeating Group node (these will not be shown on the view – they are used to aid in the calculations)

Name |
Data Type |

ElapsedTime | Text (string) |

TotalMinutes | Decimal (double) |

5) Add one final field to calculate the sum of all the entries – this should be added to the myFields node…not the Repeating node

Name |
Data Type |

TotalTime | Text (string) |

Your final data structure should look like this:

And your form could look like this:

__Adding the expressions…let the fun begin!__

The first step is to convert the StartTime and EndTime values to minutes – this makes the calculation a bit easier. In addition, we don’t want to execute this calculation if either the StartTime or EndTime is blank. So to perform this “conditional statement”, we’ll use the logic explained in this blog entry.

**Step 1: Parse the Hours and Minutes**

1) We first need to parse the “hours” and convert this to minutes by multiplying that value by 60. To do this we will use the “substring-before” function to look for the colon (“:”) in the time field and extract the value before the colon:

substring-before(../my:EndTime, ":") * 60)

substring-before(../my:StartTime, ":") * 60

2) To each of these values, we need to add the minutes that were entered after the colon. Now when time values are stored in the underlying XML, they are stored in this manner: hh:mm:ss. So to pull just the minutes entered, we will use a combination of the “substring-before” and “substring-after” functions since we need the value entered “after” the first colon and “before” the last colon:

substring-before(substring-after(../my:EndTime, ":"), ":")

substring-before(substring-after(../my:StartTime, ":"), ":")

3) Now, at this point we could place each of these expressions together to get the total hours and minutes for each time entry:

((substring-before(../my:EndTime, ":") * 60) + substring-before(substring-after(../my:EndTime, ":"), ":"))

((substring-before(../my:StartTime, ":") * 60) + substring-before(substring-after(../my:StartTime, ":"), ":"))

4) Keep in mind, we don’t want this expression to execute if either the StartTime or EndTime fields are empty and we also need to subtract the StartTime total minutes from the EndTime total minutes. So to do this we will use the “substring” function in conjunction with a “condition.” The substring function has the following signature:

substring([String Value], [Starting Position], [Condition/Length])

To incorporate our expressions into the substring function, it would look like this:

Substring([EndTime – StartTime], 1, EndTime != “” and StartTime != “”)

EndTime expression:

((substring-before(../my:EndTime, ":") * 60) + substring-before(substring-after(../my:EndTime, ":"), ":"))

StartTime expression:

((substring-before(../my:StartTime, ":") * 60) + substring-before(substring-after(../my:StartTime, ":"), ":"))

Starting position: 1

Condition expression (that if true, evaluates to the length of what we want to return so we use the “string-length” function to get the length of our initial expression):

(../my:StartTime != "" and ../my:EndTime != "") * string-length(((substring-before(../my:EndTime, ":") * 60) + substring-before(substring-after(../my:EndTime, ":"), ":")) - ((substring-before(../my:StartTime, ":") * 60) + substring-before(substring-after(../my:StartTime, ":"), ":")))

So our final expression for the TotalMinutes field would look like this:

substring(((substring-before(../my:EndTime, ":") * 60) + substring-before(substring-after(../my:EndTime, ":"), ":")) - ((substring-before(../my:StartTime, ":") * 60) + substring-before(substring-after(../my:StartTime, ":"), ":")), 1, (../my:StartTime != "" and ../my:EndTime != "") * string-length(((substring-before(../my:EndTime, ":") * 60) + substring-before(substring-after(../my:EndTime, ":"), ":")) - ((substring-before(../my:StartTime, ":") * 60) + substring-before(substring-after(../my:StartTime, ":"), ":"))))

**Step 2: Convert resulting Total Minutes to hours and minutes**

This expression will use the same basic logic we used above: first divide the resulting total minutes field by 60 to see how many hours have elapsed. If the result of that division contains a decimal point (i.e. 90 minutes / 60 = 1.5) then parse the value before the decimal point (for the hours) and then use the “mod” function to return the balance of the minutes.

1) We need to divide the TotalMinutes field by 60 to get how many hours have elapsed; however, we also need to check if the resulting value contains the decimal point. So the first expression will use the “substring” function so we can incorporate the conditional test. For the conditional test, we will use the “contains” function to see if the result contains the decimal point:

contains(../my:TotalMinutes div 60, ".")

So our initial expression would be as follows: this incorporates the “concat” function so if the resulting value contains a decimal point, we will parse that value, concatenate a colon and the concatenate the result of TotalMinutes mod 60:

substring(concat(substring-before(../my:TotalMinutes div 60, "."), ":", ../my:TotalMinutes mod 60), 1, contains(../my:TotalMinutes div 60, ".") * string-length(concat(substring-before(../my:TotalMinutes div 60, "."), ":", ../my:TotalMinutes mod 60)))

2) If the resulting expression does not contain a decimal point, then we will simply concatenate a colon with the results of TotalMinutes mod 60:

substring(concat(../my:TotalMinutes div 60, ":", ../my:TotalMinutes mod 60), 1, not(contains(../my:TotalMinutes div 60, ".")) * string-length(concat(../my:TotalMinutes div 60, ":", ../my:TotalMinutes mod 60)))

3) So our final expression for the ElapsedTime field would be as follows:

concat(substring(concat(substring-before(../my:TotalMinutes div 60, "."), ":", ../my:TotalMinutes mod 60), 1, contains(../my:TotalMinutes div 60, ".") * string-length(concat(substring-before(../my:TotalMinutes div 60, "."), ":", ../my:TotalMinutes mod 60))), substring(concat(../my:TotalMinutes div 60, ":", ../my:TotalMinutes mod 60), 1, not(contains(../my:TotalMinutes div 60, ".")) * string-length(concat(../my:TotalMinutes div 60, ":", ../my:TotalMinutes mod 60))))

**Step 3: Final Formatting - the ActualTime field**

The way the expression is written for the ElapsedTime field, if the resulting minutes is less than 10, only a single value will be returned (i.e. 0:9). Because of this, we want to test for this condition and if the minutes are less than 10, then concatenate a zero (“0”) before that value so the time appears correct. Now this expression could possibly have been incorporated into the ElapsedTime expression but for ease and clarity, I separated these two steps into different fields.

This expression uses the “string-length” function to determine the length of the string after the colon. If the length is 2 (minutes are greater than 9) then simply concatenate the hours, a colon and the minutes. However, if the length is 1 (minutes are less than 10) then concatenate the hours, a colon with a zero (“:0”) and the minutes. Like before, we will use the “substring” function with a condition statement to determine what to return:

concat(substring(concat(substring-before(../my:ElapsedTime, ":"), ":", substring-after(../my:ElapsedTime, ":")), 1, (string-length(substring-after(../my:ElapsedTime, ":")) = 2) * string-length(concat(substring-before(../my:ElapsedTime, ":"), ":", substring-after(../my:ElapsedTime, ":")))), substring(concat(substring-before(../my:ElapsedTime, ":"), ":0", substring-after(../my:ElapsedTime, ":")), 1, (string-length(substring-after(../my:ElapsedTime, ":")) = 1) * string-length(concat(substring-before(../my:ElapsedTime, ":"), ":0", substring-after(../my:ElapsedTime, ":")))))

**Step 4: ****Create the TotalTime expression for keeping a running total of the elapsed time**

The last step is to create the TotalTime expression – this is similar to the ActualTime expression except we now incorporate the “sum” function to get the running total:

concat(substring(concat((sum(../my:group1/my:group2/my:TotalMinutes) - sum(../my:group1/my:group2/my:TotalMinutes) mod 60) div 60, ":", sum(../my:group1/my:group2/my:TotalMinutes) mod 60), 1, (sum(../my:group1/my:group2/my:TotalMinutes) mod 60 > 9) * string-length(concat((sum(../my:group1/my:group2/my:TotalMinutes) - sum(../my:group1/my:group2/my:TotalMinutes) mod 60) div 60, ":", sum(../my:group1/my:group2/my:TotalMinutes) mod 60))), substring(concat((sum(../my:group1/my:group2/my:TotalMinutes) - sum(../my:group1/my:group2/my:TotalMinutes) mod 60) div 60, ":0", sum(../my:group1/my:group2/my:TotalMinutes) mod 60), 1, (sum(../my:group1/my:group2/my:TotalMinutes) mod 60 < 10) * string-length(concat((sum(../my:group1/my:group2/my:TotalMinutes) - sum(../my:group1/my:group2/my:TotalMinutes) mod 60) div 60, ":0", sum(../my:group1/my:group2/my:TotalMinutes) mod 60))))

**Step 5: Test!**

Enter a Start and End Time in the form of: h:mm AM(PM), such as: 8:00 AM and 5:00 PM – the ActualTime field should display the difference (as 9:00) and if you continue adding rows, the TotalTime field should reflect the running total.

This functionality allows you to create elapsed time scenarios that work in both client and browser forms without writing one line of code!

Scott Heim

Support Engineer