title: Google Apps Script: In spreadsheet, how to select cell with date format value in it and change it to that date plus 7 days (1 week)
body: <p>I have a google spreadsheet and want to use Google Apps Script to activate cell B1 in the first sheet (currently formatted as a date - 1/27/2014) and change it to that date plus 7 days (2/3/2014). I am pretty new to Google Apps Script and have only successfully written a couple other functions. What I was thinking so far was:</p>
  
  <pre><code>function changeDate() {
  
      var ss = SpreadsheetApp.getActiveSpreadsheet();
      var sheet = ss.getSheets()[0];
  
      var b1_date = sheet.getRange("B1").getValue();
      //...
  
  }
  </code></pre>