Thanks for posting your question in the Community. I'm here to help with pulling up a list of all estimates to multiple customers during a given period of time.
QuickBooks Online offers multiple reports for viewing transactions, which can display all of the estimates for a given period of time. One report that can provide this is the Transaction List by Date, which can be filtered just for estimates. Here's how:
Select Reports on the left navigation menu.
Enter Transaction List by Date in the Report Search Bar.
Click Customize in the top right-hand corner.
Select Filter and select the drop-down arrow next to Transaction Type and select Estimate.
Choose the time period that you'd like for the report to display in the top left-hand corner.
Select Run Report.
I've included a brief video to serve as a demonstration:
Another option is the Transaction List by Customer, which will display much of the same information, but will group the transactions by customer. The steps for customizing this report to display only estimates will be the same as those for Transaction List by Date.
I'm confident that either of these reports will help you to find the information that you need.
Should you expect to frequently need to view information on all of the estimates for a given period, you may wish to consider memorizing the report, as this will save it with the current customization settings. The following article contains additional information on this: Memorize a Report.
The Community always has your back and is happy to assist with anything you may need. Take care.