Dynamics 365 Business Central AS 101 Lesson 10: Comparison Period v. Comparison Date
Dynamics 365 Business Central Account Schedules uses a curious convention to determine periods of time in the column layout. The default option if you open account schedules for the very first time is Comparison Date, but I always recommend Dynamics 365 Business Central users use the other option, Comparison Period. Let’s talk about why.
I recommend using Comparison Period for Business Central users.
Comparison Period is more flexible
If you read the Dynamics 365 Business Central help on this topic, you’ll find a fairly long listing of what you can do with comparison period and a very short entry on what you can do with comparison date. That’s because you can just do a lot more with comparison period. Comparison dates use standard Dynamics 365 Business Central date formulas that are more appropriate for use in payment terms and journal entries.
Comparison Date Formula Field
This field contains a date formula that specifies which dates should be used to calculate the amount in this column.
The program uses this formula to calculate the amount from the comparison period in relation to the period represented by the date filter on the report request.
For example:
Comparison Period Formula Field
This field contains a period formula that specifies which accounting periods should be used to calculate the amount in this column. An accounting period does not have to match the calendar, but each fiscal year must have the same number of accounting periods, even though each period can be different in length.
The program uses the period formula to calculate the amount from the comparison period in relation to the period represented by the date filter on the report request. The comparison period is based on the period of the start date of the date filter. The abbreviations for period specifications are:
Abbreviations and descriptions for period specifications
Examples of formulas:
Comparison Period formulas and their descriptions
Comparison Period reduces the possibility of accidentally reporting incorrect numbers
This is a classic example of an account schedule I see in use all the time by beginning account schedule users. Here is a 12 month net change column layout design using Comparison Date.
Using Comparison Date in a 12 month net change column layout design
Here is a 12 month net change column layout design using Comparison Period.
Using Comparison Period creates fixed fiscal periods when you report
The primary difference between the two methods is that comparison period fixes the fiscal periods when you report, while comparison date is wholly dependent upon what your date filter is set for.
If you are producing your financial statement package at the end of the month, you’ll produce your income statement, balance sheet, statement of cash flows and any other reports you use with the date filter set for the end of the month you are reporting against. When you get to this report, using comparison date, you’ve got to remember to manually switch your date filter to the end of the year, because the formulas calculate backward from the date set in order to produce the report.
This is very risky because if you forget to do this, you can very easily forget to not switch the date. In this case, the report will still produce 12 columns of numbers, but they’ll be wrong, because they are using the date from your date filter as your “year-end” date, which is incorrect. When using the comparison period setup in the way shown above, you can change your date filter all you want within the current fiscal year and you’ll get the same correct result every time.
If you use an accounting period other than calendar month, you’ve got to use Comparison Period
You just can’t use comparison date if you’ve got 13 periods, if you use a 4-4-5 convention, or if you’ve got anything other than 12 calendar months defined as your fiscal periods.
Comparison Date, what the heck’s it good for?
Despite everything you’ve read above, comparison date does have one really good use, and that is if you need to report on something on a daily or even weekly basis. Comparison period can’t go below the fiscal period unit, but comparison date sure can. Here’s an example of a column layout that defines time periods of daily for a week. Remember, in order for this to work, the date filter needs to be set to the last day of the week.
Comparison Date comes in handy for daily and weekly reports
This posting is part of the Dynamics 365 Business Central Account Schedules 101 series. Find the entire list of lessons here.