Thank you for joining the thread, @JD374. I'll take care of this query about adding daily info from a weekly timesheet into an invoice in QuickBooks Online (QBO).

You can create a weekly timesheet, then mark it as billable. Choose the correct employee or vendor from the first drop-down menu, then select the correct week. Under the Details section, choose the correct project or customer. Enter the hourly rate and the number of hours for Monday to Friday. Fill out the other drop-down menus as necessary. See this screenshot for reference:

After you save this weekly timesheet, proceed to create a new invoice. Here's how:

1. Go to the + New menu, then select Invoice. 
2. Choose the correct project or customer under the Customer drop-down menu. 
3. A pop-up window will appear on the right-hand side, click the Add link for each of them. 

Let's take the screenshot above as an example. Your invoice will look like this:

The Service Date column is the date for the billable time. Using this example, from the top going to the bottom it's from Monday to Friday. The Qty column is the number of hours, and the Rate is the billable rate per hour. The Amount column shows the total billable amount per day. Check out this article for more information about this process: Track and manage timesheets in QuickBooks Online. 

In case you have QuickBooks Time, take a look at this article instead: Track and manage QuickBooks Time in QuickBooks Online and QuickBooks Online Payroll. 

Post a reply if you have other questions about timesheets in QBO. I'll get back to you as soon as I can. Have a nice day!