You have a dashboard that contains a parameter named Start Date.

Create a data source based on the Excel worksheet and create a calculated field based on Start Date. Add the calculated field to the extract filter.

Create a custom SOL query to define the data source and create a calculated field based on Start Date. Add the calculated field to the extract filter.

Create a custom SOL query that references Stan Date in the WHERE clause.

Create a data source based on the Excel worksheet and create a calculated field based on Start Date. From the Data pane, add the calculated field to the data source filter