Events in the real world have an annoying habit of not occurring on your financial model period end dates. This modelling guide gives you reusable code to calculate partial period factors. This will allow you to easily deal with events that occur in between period end dates.

1. Financial Modelling
HANDBOOK
How to model
PARTIAL
PERIOD FACTORS
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3. ABOUT THE FINANCIAL
MODELLING HANDBOOK
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reduces error, speeds up development time and lowers
cost. The Financial Modelling Handbook is a collaborative,
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4. Financial Modelling
HANDBOOK
ANDREW
Andrew Berkley is Managing
Director and Lead Modelling
Instructor at F1F9. Andrew is a
Chartered Accountant with a
background in financial advisory
and business education.
financialmodellinghandbook.com

5. Financial Modelling
HANDBOOK
How to model
PARTIAL
PERIOD FACTORS
Events in the real world have an annoying habit of not
occurring on your financial model period end dates.
This modelling guide gives you reusable code to calculate
partial period factors. This will allow you to easily deal with
events that occur in between period end dates.
DOWNLOAD THE EXCEL FILE THAT
ACCOMPANIES THIS MODELLING GUIDE

6. Financial Modelling
financialmodellinghandbook.com
HANDBOOK
SET UP THE TIMELINE
1
1
Import timeline start date and
periodicity assumptions.
2
2
Calculate period start dates. We
tend to avoid EOMONTH due to
Analysis ToolPak compatibility
issues. The formula here does the
same job.

7. Financial Modelling
financialmodellinghandbook.com
HANDBOOK
CALCULATE DAYS IN YEAR
3
4
3
Use periodicity assumption to
calculate period end date.
4
Use period start and end dates to
calculate the number of days in a
period. Subtracting one date from
another in excel gives the number
of days between the two dates.

8. Financial Modelling
HANDBOOK
financialmodellinghandbook.com
DAYS PRE TARGET DATE
5
5
MAX(0, (MIN($F71, J73) - MAX($F70, J72) + 1))
Subtract the greater of the model start date and the current period
start date, from the lower of the acquisition date and the current
period end date, but don’t allow negative numbers.
This returns the days before the acquisition date.

9. Financial Modelling
HANDBOOK
financialmodellinghandbook.com
CALCULATE PPF
6
6
Divide the days in the pre-acquisition period (calculated at Step 5) by
the total days in period (calculated at Step 4) to give the partial period
factor.

10. Financial Modelling
HANDBOOK
financialmodellinghandbook.com
CALCULATE PPF
7
7
Repeat the process for post acquisition date PPF.