Hi ComCom,
Yes you can import the hours as timesheet entries using an IIF file. The formatting of the file and how to produce those are detailed in this Help Article
Alternatively, you could use one of the third party data import utilities that you can find in the Intuit Marketplace, Zed Axis is one that I am the publisher of and can import Time Entries in Excel format directly into QuickBooks Desktop.
Hope that helps.
Steve