This article describes how to extend the default calculation engine by implementing a custom calculation engine using the Aspose.Cells library. By loading an existing Excel file or creating a new one, we can use the methods provided by Aspose.Cells to implement a custom calculation engine and get the results. Finally, we save the modified Excel file to disk....day to the system date. So if the current date is 27/07/2023, then...above sample code, the value(date time) of A1 with custom engine...