Overview
Conversion from clock time to decimal time can create discrepancies on invoices between the session list and the invoice total due to rounding on the conversion.
To prevent these rounding issues use 15 minute increments in your sessions by setting your session resolution on the locations - states page to 15.
Article Sections
Background
From time to time, you may see a discrepancy with totals on your Invoice. This can be explained with a simple example:
Example 1
Let's say you have two students, Christopher and Dixie who have 3:50 hours and 3:35 hours to be invoiced respectively and you create an invoice for them with a rate of $52/hour.
The total hours on the invoice is 7:25 and the amount is $385.67.
Now let's say your customer wants the hours on the total page displayed as hours and decimal hours, the total display of hours as hours and decimal hours is 7:25 or 7.4166666667
(25/60 = .4166666667 so therefore 7:25 = 7.416666667) and this now equals $358.6666666 or when rounded, $385.67. Still correct.
However, your customer doesn't like all of the decimal places and asks you to round to two decimal places. This now results in a display of 7.42 hours.
The problem arises in that 7.42 times $52 is $385.84, but we've already calculated the invoice as $385.67. We're apparently 17 cents out.
Of course, both values are correct, but an "error" has been introduced by the display of hours as 7.42 instead of 7.4166666667.
Example 2
The issue continues in that the detail of hours on the second page is rounded as well. (Assuming you have hours and decimal hours displayed in the invoice detail.) The detail pages always displays decimal hours to two decimal places.
Now let's say your customer adds up the HRS column of the Invoice to ensure accuracy. Another issue ensues.
Because of rounding, the second page will display 3:50 as 3.83
(50/60 = .8333333333 = 3.83333333333) and 3:35 will be 3.58 (35/60 = .5833333333 = 3.5833333333).
3.833333333 multiplied by $52.00 will equal $199.3333 and 3.58333333 multiplied by $52.00 will equal $186.33333.
When added, those figures equal 385.66663 which when rounded equals $385.67 (the total on the first page)
However, each individual figure will be rounded and displayed to 2 decimal places on the 2nd page and these figures are the ones that your customer will be adding.
Therefore, you will be left with $199.33 and $186.33. When added, those figures total $385.66.
The invoice now appears to be $.01 off.
This example is for 2 students. Now imagine you have 20 or even 50 students on the Invoice. Now imagine how far off the Invoice would appear.
Consequence
This means that you can't add up the totals from the detail pages and expect to get the same total as the value on the first page unless your session resolution is set to a time that has a perfect conversion. Behind the scenes, Oases is tracking all of the 'chopped' off decimal places and adding them at the end to get an accurate total. The total Oases is displaying is the most accurate it can be and ensures that your organization is Invoicing the correct amount.
Prevention
To prevent rounding errors set your session resolution to a figure that does not invite rounding issues. Such as 15 minute increments which will be 0.25, 0.5 etc, a perfect conversion.
Consider also the Service Hours of the student. If the service hours are not a perfect conversion and rounded down to the nearest 15 minute block your final invoice which adjusts for the student PPA will encounter rounding issues.