An .xls file is a Microsoft Excel spreadsheet file, created with a version of Excel prior to Excel 2007. A .vcs file is a vCalendar Event File, which contains information about an event that can be opened with a variety of calendar or scheduling programs. A properly formatted .xls file can be converted to a .vcs file with the ABC Amber Excel Converter.
Download, install and run ABC Amber Excel Converter (see "Resources").
Click the “Open” button and browse to the .xls file you wish to convert, then click “Open” to import the file to the program.
Click the “vCalendar” link in the “Hint Window” that automatically opens.
Choose the location where you want to save the converted file, then click “Save” to create the .vcs file.