Probability of a full week's revenue based on the first two days

We are looking for a probability model ideally built in Excel where we can input our own data into it.

The data will have column A, which is the date of each day, and column B, which is the revenue for each day. These columns will be filled with 5+ years worth of historical data which will be provided to you.

From there, we'd like the ability to input the revenue of the first two days of future weeks (i.e. Monday and Tuesday), and then the spreadsheet should tell us the predicted revenue of that full week based on the historical data with a confidence percentage.

It should also show a confidence percentage of how likely the week's revenue will surpass a customisable threshold figure.

Once a week is complete, we should also be able to add that full week's data to the spreadsheet which then updates the model with more data to make it more accurate over time.