---
title: "Explanation of the date functionality when generating a billing schedule"
slug: "abonnements-explication-de-la-fonctionnalité-des-dates-lors-de-la-génération-déchéancier"
updated: 2025-10-10T11:22:00Z
published: 2026-01-07T10:04:01Z
canonical: "help.frisbii.com/abonnements-explication-de-la-fonctionnalité-des-dates-lors-de-la-génération-déchéancier"
---
> ## Documentation Index
> Fetch the complete documentation index at: https://help.frisbii.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Explanation of the date functionality when generating a billing schedule
Axel and Candace are still struggling with the multitude of dates on a subscription. Linda is keen to make them understand this essential part of the subscription, and launches into a detailed explanation.
## The Date fields
The generation of a billing schedule on a subscription record is conditioned by the fields:
- Start date
- Start of invoicing period
- End of invoicing period
- Frequency
| **Start date** | Date | - Subscription start date. - The first period of the subscription is determined from this date. |
| --- | --- | --- |
| **Start of invoicing period** | Date | - Start date of the invoicing period. - Determines whether an invoice is generated for a given period (see Figure 2: Calendar Period). |
The *Start Date* and *Start of invoicing period* fields support subscriptions over rolling periods and subscriptions over defined periods (such as calendar periods).
| Initial End Date | Date | |
| End of invoicing period | Formula (Date) | - If the subscription has not been renewed :
repeats the data entered in the Original End Date field. |
The *Start Date* and *End Date* fields on invoice records generated from the subscription are automatically populated on creation.
| Frequency | Picklist | Billing frequency: - Monthly : Every month
- Bimonthly: Every 2 months
Quarterly: Every 3 months
Four-monthly: Every 4 months (from Spring '20 onwards)
Half-yearly: Every 6 months
Annual: Every year Influences the calculation of the number of occurences. |
## Figure 1: Rolling period without prorating
The diagram below represents a rolling period billing without prorating. The Start date of the invoicing period is equal to the Start Date and the Initial End Date is entered to be equal to the last day of the period.
Example: a 3-month monthly subscription taken out on 10/01 is invoiced the same day, and every 10th of the following months.
## Figure 2: Rolling period with prorating
The diagram below represents a rolling pro rata invoicing period. The Start date of the Invoicing Period is different from the Start Date and the Initial End Date is entered to be equal to the last day of the period. A pro-rata is applied on the first invoice by different dates on the invoice line items.
Here is the article that explains the [Subscriptions - automatic prorating](/frisbii-app/docs/en/abonnements-la-proratisation-automatique).
**Example:** a 3-month monthly subscription taken out on 10/01. It should be invoiced every 10th of the month (= Start date) but the first month the service is only provided to the customer from 20/01. We therefore want to invoice it only from 20/01 (= Start of billing period) to 09/02. A pro rata should therefore be applied.
Once the invoice records have been generated, the invoice dates are initialized on the records via a second process.