How to properly indicate that last 24 hours data may or may not included in the sentence?

I have a visual chart on my website and I update this chart once or twice each day automatically. However, I would like to tell my users that this chart (contains data usages) may or may not include last 24 hours. And let them know that I will make sure everything is included when an invoice is issued.

Is this sentence correct?

Data* may or may not contain usages for past 24 hours. Your invoiced total will be displayed once an invoice is issued.

* Data: Represents data in visual chart.

How can I make sure viewers acknowledge this properly?