Hello @Hisatsune (Inc. AXLBIT) Thanks you for reaching out to us!
I see, you are using APIs to estimate customers billing amount and would like to know what it means the term "the current billing period" used on the website.
Billing periods is the date range for which we bill the customer monthly. In case of Azure plans as in your case, the billing period is standard 'starting from 1st of a month to end of a month'.
However, for legacy offers, billing period used to be the start of the subscription to the next month. For example: If subscription was created on 17th of a month, then its billing period would be 17th of this month to 16th of next month. Next billing cycle would 17th of next month to 16th of the other month and so on.
For all Azure plans irrespective of Partner led, customer led or Field led, billing period is 1st of a month to end of that month.
Hope this clarifies!
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