Note the formula in column H, which generates TRUE/FALSE. You can obviously replace this logic with whatever you want.

I set a daily 8am trigger to run this script, which sends notifications for the rows that are marked TRUE:

  function sendReminderEmails() {
  var sheet = SpreadsheetApp.getActiveSheet();
  sheet.getRange('B1').setValue("");
  SpreadsheetApp.flush();
  sheet.getRange('B1').setValue("=TODAY()");
  SpreadsheetApp.flush();
  var headerrows = 3;
  var numColumns = 8;
  var subjectColumn = 1; // one-based, i.e. column A is 1, B is 2 etc.
  var addressColumn = 2;
  var conditionColumn = 8;
  var startRow = 1 + headerrows; // First row of data to process
  var numRows = sheet.getLastRow()-headerrows; // Number of rows to process
  var dataRange = sheet.getRange(startRow, 1, numRows, numColumns);
  var data = dataRange.getValues();
  for (var i in data) {
    var row = data[i];
    if (row[conditionColumn-1]) {
      var emailAddress = row[addressColumn-1];
      var message = 'Reminder: ' + row[subjectColumn-1];
      var subject = message;
      MailApp.sendEmail(emailAddress, subject, message);
    }
  }
}