Sales Data Cleanup & Standardization

I have an Excel workbook packed with sales records collected from several sources and the date fields are all over the place—some are U.S. style, others European, some are stored as text, and a handful even show up as serial numbers... (Budget: ₹750 - ₹1250 INR, Jobs: Data Analysis, Data Management, Data Processing, Excel, Excel Macros, Excel VBA, Visual Basic, Visual Basic for Apps)