If you have historical timesheets data in Excel, you can import everything in Clockify as time entries, so your reports can include all your past and future data.
Import will create all the necessary projects, tasks, clients, users, and time entries. All you need to do is provide the file
Importing timesheets is an extra feature, which you can enable by upgrading your workspace Enterprise plan.
You can try out the feature for free by activating the free 7-day trial (no credit card required)