concatenate date and time in google spreadsheet

Question

I have a script that imports events from spreadsheets into calendar:

function caltest1() {
  var sheet = SpreadsheetApp.getActiveSheet();
  var startRow = 2;  // First row of data to process
  var numRows = 3;   // Number of rows to process
  var dataRange = sheet.getRange(startRow, 1, numRows, 5);
  var data = dataRange.getValues();
  var cal = CalendarApp.getDefaultCalendar();
  for (i in data) {
    var row = data[i];
    var title = row[0];  // First column
    var desc = row[1];       // Second column
    var tstart = row[2];
    var tstop = row[3];
    var loc = row[4];
    //cal.createEvent(title, new Date("March 3, 2010 08:00:00"), new Date("March 3, 2010     09:00:00"), {description:desc,location:loc});
    cal.createEvent(title, tstart, tstop, {description:desc,location:loc});
 }
}

The script works fine if my spreadsheet contains the data like:

Title      Description    Start               Stop                  Channel
Mr Dear    no drinks      5/6/2014 20:55:00   5/6/2014 21:57:00     what ever

But it does not work if I create my own date =CONCATENATE($D4, " ",$G4), given that D4 has a date and G4 has time combined into a single cell Date and time. I figured because it senses that concatenate creates a plain text and not a time formatting, but how can I fix it?

Answer 1

In spreadsheets, dates have a native value of an integer representing the number of days since december 31 1899 and time is a decimal value which is the fraction of a day ( 6 hours = 1/4 of a day for example , 0.25 day).

So when you add DATE+TIME (integer+decimal) in a spreadsheet you get a full date with time .

So the answer (as you noticed it in your comment on the other answer) is logically to ADD both values. That's actually the reason spreadsheets are build like that ! (to make it easy to use date and time)

Use the formula =D2+E2 in a new column and you get a complete date object directly useable in JavaScript.

In Javascript date and time are the same objects, there is no time object that has no date and no date without time : their native values are milliseconds counted from January 1 1970 at midnight (which is an integer).