Sets the date and time when the file was last written to.
fileInstance.LastWriteTime = newLastWriteTime
|string||newLastWriteTime||The new date and time when the file was last written to.|
//anyFile is a instance of file type.
anyFile.LastWriteTime = "3/04/2016 4:13:00";
It's a wrapper of the System.IO.FileInfo.LastWriteTime.
The date and time string is converted to the C#'s DateTime type by the System.DateTime.Parse(String) method.
Links for reference