Academy ↓
Back up Spreadsheet Tab
Make a copy and rename to BACKUP plus the Date of the backup. Execute this automatically via Triggers in your Apps Script
function createBackUpTab() {
var ss = SpreadsheetApp.getActiveSpreadsheet()
var weekly = ss.getSheetByName("WEEKLY")
var date = Utilities.formatDate(new Date(),"GMT","yyyy-MM-dd" )
weekly.copyTo(ss).setName("BACKUP: " + date )
}