Time phased data for billing.

Hello,

I'm trying to make a Financial report for projects through power BI. We've set a different Billing rate for different tasks and the billing amount would be (Task work*Billing rate). What we want is this Billing amount time phased, so that we have a the billing amount for each week and we can forecast the budget per week. We get the data for Task names, billing rate, task work and billing amount from one query and 'Time by Day' from another. However, after selecting the Time by Day, there's an error. 

I've attached some snapshots for reference. Would you tell me what is a better way to do this? And why I am getting the error?

Thank you.