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Administrator Guide
Last Updated: 2026-03-13
Concept: Proration Methods for Consolidated Billing Schedules

Concept: Proration Methods for Consolidated Billing Schedules

When you create consolidated billing schedules with a spread-even billing method for customer contracts, you can prorate partial periods for installments by selecting an option from the
Proration Method
 prompt on these tasks:
  • Create Billing Schedule for Customer Contract
  • Create Billing Template for Customer Contract
Workday supports these proration methods:
Option
Description
Actual Calendar Days
Prorates amounts based on the actual number of calendar days in each billing period, including leap years. Prorated amounts due to stub periods vary depending on the number of days in each period. Use this method when proration must align precisely with real calendar dates and you require day-level accuracy.
Fixed Year 365 Days
Calculates installment amounts by normalizing service time against a constant 365-day year, regardless of leap years. Workday counts actual service days within each billing period as-is, including February 29 when applicable. Use this method when you want stable, uniform daily pricing and prefer to avoid billing fluctuations caused by leap years.
30 Day Month
Assumes every month has 30 days and every year has 360 days to ensure charges don't fluctuate by calendar period. Use this method when you want consistent monthly billing amounts.
This method doesn't apply to
Billing Frequency
 values of
Weekly
 or
Calendar Week
.
Monthly Plus Daily
Allocates amounts evenly to each full billing period and prorates partial periods using a standardized daily rate. To calculate partial periods, Workday divides the number of remaining days by an average period length (365 ÷ 12 for monthly-based periods), ensuring consistent proportion regardless of the actual number of days in a calendar month. Use this method when you want stable amounts for complete periods with predictable daily proration for partial periods at the beginning or end of the term.
By Calendar Month
Allocates amounts based on whole calendar months and calculates partial periods as a fraction of the corresponding calendar month. Workday considers the actual number of days in each month, including leap years, for this calculation. Use this method to distribute amounts according to calendar month boundaries, rather than evenly by day across the entire term.
This method doesn't apply to
Billing Frequency
 values of
Weekly
 or
Calendar Week
.

Example

You want to create a consolidated billing schedule for your customer contract with a monthly billing installment frequency from 2025-01-10 to 2025-04-02. You want to use a proration method to calculate installment amounts for partial periods when you use the spread-even billing method. You have a line amount of 6,000.00 USD on your contract.
From the
Create Billing Schedule for Customer Contract
 task, you select
Consolidated Billing Schedule
 from the
Schedule Type
 prompt.
You define these values on the
Installment
 tab of your billing schedule:
Configuration
Value
Billing Method
Spread Even
Billing Frequency
Monthly
Billing Period
Current
From Date
01/10/2025
To Date
04/02/2025
These are the billing date ranges for each installment:
  • Installment 1: 2025-01-10 to 2025-02-09
  • Installment 2: 2025-02-10 to 2025-03-09
  • Installment 3: 2025-03-10 to 2025-04-02
To calculate proration amounts for billing installments, you select an option from the
Proration Method
 prompt. Workday calculates the installment amounts based on your selected proration method:
Proration Method
Installment 1
Installment 2
Installment 3
Total Amount
Actual Calendar Days
2,162.79
2,162.79
1,674.42
6,000.00
Fixed Year 365 Days
2,240.96
2,024.10
1,734.94
6,000.00
30 Day Month
2,195.12
2,195.12
1,609.76
6,000.00
Monthly Plus Daily
2,151.28
2,151.28
1,697.44
6,000.00
By Calendar Month
2,161.12
2,161.12
1,677.76
6,000.00