@WinstonSmith Well I don't know of a good solution at the moment.. If you are willing to do some "hacking" of your own then you could try and add a script to your spreadsheet that automatically adds a date once a new row is inserted into the document. This is maybe not ideal, but it might work for you. How I would do that is probably to add another column to the spreadsheet and then let it be empty when you append rows through IFTTT. Then in the document go to Tools -> Script editor... and in the script file that is created remove the auto generated script and instead enter the following:
function onEdit(e) {
var columnIndex = 1; // Index 1 is the first column (column A)
var activeSheet = e.source.getActiveSheet();
var range = activeSheet.getRange(1, columnIndex, activeSheet.getMaxRows(), 1);
var firstColumn = range.getValues();
for (var i = 0; i < firstColumn.length; i++) {
if (firstColumn[i][0] == "") {
firstColumn[i][0] = new Date();
}
}
range.setValues(firstColumn);
}
Change the columnIndex parameter on the second line to correspond to the index of the column you want the date to be added to. This script will input the current time and date to any empty row in that column. If you try this, then please try it on a non-important document to make sure that it works for you before adding it to the real document. I have only tried this within goggle spreadsheets itself and not through IFTTT.