The Documents - Today section of your Dashboard provides a summary of your key transactions for the current day, both in dollars and number of documents. The totals for Sales, Cancellations, and Refunds are an aggregate total for the current calendar day, across all Shopify stores you have connected to your weintegrate account.
Note that these totals are updated near real-time, so as these documents are processed in Shopify the values on your Dashboard will update (you may have to click your browser fresh for the latest totals)
Click here to learn about setting the Your Dashboard - Your Documents Month to Date account default for integrating with QuickBooks Online.