Understanding Aria Operations Chargeback billing period alignment with UTC
Article ID: 453342
Updated On:
Products
Issue/Introduction
- Generated bills accurately reflect usage and pricing up to the specific start time of the selected end date.
- Total charges may appear lower than manual full-month calculations if the selected end date is set to the last day of the current month, as the calculation stops at 12:00 AM UTC.
- The UI displays the exact timestamp for the billing period coverage before generation.
Environment
VMware Aria Operations 8.18.x
VMware Cloud Director 10.6.x
Cause
The Aria Operations billing engine processes calculations based on Coordinated Universal Time (UTC). When an end date is selected in the UI (e.g., July 31st), the engine interprets it as 12:00 AM UTC. This corresponds to the early morning of that day in UTC time, meaning the remaining hours of that calendar day are not included in the calculation.
Resolution
To include a complete calendar day or full month in the billing period, select the following day as the end date to account for the UTC timestamp structure.
1. Log in to the Aria Operations / Chargeback UI.
2. Navigate to the bill generation screen.
3. Set the Start Date to the beginning of the desired period (e.g., July 1st).
4. Set the End Date to the next day past the intended period (e.g., August 1st to cover all of July) to ensure the required days are fully covered.
5. Verify the timestamp interpretation in the summary before generating the bill.
Additional Information
For pro-rated allocation changes (e.g., increasing CPU mid-month), Aria Operations calculates the daily price as follows: Daily Price = (Total Allocation * Base Rate) / Number of Days in Month The total bill is the sum of these daily pro-rated values.
Example Calculation:
- Total CPU Allocation: 200
- Base Rate: 1.0
- Days in Month: 31
- Calculated Daily Price:
(200 * 1) / 31 = 6.45 - 30-Day Truncated Bill:
30 * 6.45 = 193.55 - 31-Day Full Month Bill:
31 * 6.45 = 200.00
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