added time info

Author: bandersmsft

articles/cost-management-billing/manage/enterprise-api.md

@@ -12,6 +12,8 @@ ms.author: banders
 # Overview of Reporting APIs for Enterprise customers
 The Reporting APIs enable Enterprise Azure customers to programmatically pull consumption and billing data into preferred data analysis tools. Enterprise customers have signed an [Enterprise Agreement (EA)](https://azure.microsoft.com/pricing/enterprise-agreement/) with Azure to make negotiated monetary commitments and gain access to custom pricing for Azure resources.
 
+All date and time parameters required for APIs must be represented as combined Coordinated Universal Time (UTC) values. Values returned by APIs are shown in UTC format.
+
 ## Enabling data access to the API
 * **Generate or retrieve the API key** - Log in to the Enterprise portal, and navigate to Reports > Download Usage > API Access Key to generate or retrieve the API key.
 * **Passing keys in the API** - The API key needs to be passed for each call for Authentication and Authorization. The following property needs to be to the HTTP headers