Changing dates on linked sheets

I have a challenging task to complete and need some help. In essence we have an entry sheet which relates to a specific date and returns a result for a number of hours required. This result then needs to update a second sheet which includes that date. I am able to reference the dates but as soon as I change the date on the entry sheet, the data on the second sheet changes. Is there a simple way of retaining the data from preceding entry sheets without using copy and paste special to make it an integer rather than a formula?

I have attached the sheet.

Thanks

Uncle H