This happens because as we always co-term subscriptions to the end of the month for your convenience because doing so makes it easier to identify when the resource limits will be reset (always the first day of the month). It also simplifies the task of calculating your resource usage for a given calendar month and, finally, allows us to bill you only once per month, as we can include your overdraft charges and the charge for your new subscription term in the same invoice.
If you upgrade your subscription during the first half of a month, we’ll automatically calculate the prorated cost for the current month, which will be smaller than the normal charge, as you will only be paying for part of the month, and we’ll scale down the resource limits.
If you upgrade your subscription to a paid subscription in the second half of a month, we’ll charge you for the following month in addition to prorating the cost for the current month. In this case, your first charge will be a bit bigger than normal, as you are paying for the extra days from the current month. We will also scale down the resource limits for the current month.