google sheet email alert if expiry date - google-apps-script

Question

I have a table with 8 columns with dates. I need to track them if they are to expire, but for 3 of them I need to alert alert 3 months before and for the remaining columns, 6 months before.
I think that I am on the right track with the code below, but still not doing what it needs to be done.
I start with one month in the beginning. Can somebody help me?
function emailAlert() {
// today's date information
var today = new Date();
var todayMonth = today.getMonth() + 1;
var todayDay = today.getDate();
var todayYear = today.getFullYear();
var newToday = new Date()
var oneMonthFromToday = new Date(newToday.setMonth(newToday.getMonth()+1));
var oneMonthMonth = oneMonthFromToday.getMonth() + 1;
var oneMonthDay = oneMonthFromToday.getDate();
var oneMonthYear = oneMonthFromToday.getFullYear();
var sheet = SpreadsheetApp.getActiveSheet();
var startRow = 2;
var numRows = 100;
var dataRange = sheet.getRange(startRow, 1, numRows, 999);
var data = dataRange.getValues();
//looping through all of the rows
for (var i = 0; i < data.length; ++i) {
var row = data[i];
var expireDateFormat = Utilities.formatDate(
new Date(row[6]),
'ET',
'MM/dd/yyyy'
);
var subject = '';
var message = ' You have expiring pass. ' + '\n';
MailApp.sendEmail('lubomira.petkova88#gmail.com', subject, message);
}

Answer 1

It is not clear on your post but the code below assumed only 1 column needs to be checked. Feel free to adjust the conditions but this should be the main idea of your code.
Code:
function checkPasswordExpiry() {
// today's date information
var today = new Date();
today.setHours(0,0,0,0);
// 3 months before
var prev3Months = new Date();
prev3Months.setMonth(today.getMonth() - 3);
prev3Months.setHours(0,0,0,0);
// 6 months before
var prev6Months = new Date();
prev6Months.setMonth(today.getMonth() - 6);
prev6Months.setHours(0,0,0,0);
var sheet = SpreadsheetApp.getActiveSheet();
var startRow = 2;
// get number of rows/columns in sheet instead of manually setting it
var numRows = sheet.getLastRow();
var numCols = sheet.getLastColumn();
var dataRange = sheet.getRange(startRow, 1, numRows, numCols);
var data = dataRange.getValues();
//looping through all of the rows
for (var i = 0; i < data.length; ++i) {
var row = data[i];
var expireDateFormat = Utilities.formatDate(
new Date(row[6]),
'ET',
'MM/dd/yyyy'
);
var date = new Date(row[6]);
date.setHours(0,0,0,0);
var subject = 'Password Expiry';
var message = 'Hi ' + row[0] + ', \nYour password is expiring';
var email = 'lubomira.petkova88#gmail.com';
if(date.getTime() === prev6Months.getTime()) {
message += " in 6 months. ( " + expireDateFormat + " )";
MailApp.sendEmail(email, subject, message);
}
else if(date.getTime() === prev3Months.getTime()) {
message += " in 3 months. ( " + expireDateFormat + " )";
MailApp.sendEmail(email, subject, message);
}
else if(date.getTime() === today.getTime()) {
message += " today. ( " + expireDateFormat + " )";
MailApp.sendEmail(email, subject, message);
}
}
}
The code above does check column G whether it is already 6 months before today, 3 months before today or exactly the date. If you need to check multiple columns, just replace the conditions inside and it should still work.
Sample email:
Note that the code above should be triggered every day so it can check the data daily.
Code:
function createTimeDrivenTriggers() {
ScriptApp.newTrigger('checkPasswordExpiry')
.timeBased()
.everyDays(1)
.atHour(0)
.create();
}
Function createTimeDrivenTriggers needs to be run just once. Please see reference below.
Reference:
Time driven triggers
everyDays()
If I wasn't able to provide you the answer you are hoping for, I sincerely apologize. Feel free to comment below what are the changes that are needed to be done.