import flash.ui.ContextMenu;
import flash.ui.ContextMenuItem;
import flash.events.ContextMenuEvent;
import com.senocular.utils.SWFReader;

var swfReader:SWFReader = new SWFReader(root.loaderInfo.bytes);
var menuItemLabel:String = "SWF Publish date: "+ getSwfModificationDate(swfReader);
var cm:ContextMenu = new ContextMenu();
cm.hideBuiltInItems();
var cmi:ContextMenuItem = new ContextMenuItem(menuItemLabel);
cmi.addEventListener(ContextMenuEvent.MENU_ITEM_SELECT, onCmi_MENU_ITEM_SELECT);
cm.customItems.push(cmi);
this.contextMenu = cm;

function getSwfModificationDate($swfReader:SWFReader):String {
	var metadata:String = $swfReader.metadata;
	var swfMetadataArray:Array = metadata.split("xmp:ModifyDate>");
	var modDate:String = swfMetadataArray[1].substr(0, 19);
	var date:String = modDate.substr(0, 10);
	var time:String = modDate.substr(11, 8);
	return date + " " + time;
}

function onCmi_MENU_ITEM_SELECT(event:ContextMenuEvent):void
{
	System.setClipboard(event.target.caption);
}

import flash.ui.ContextMenu;
import flash.ui.ContextMenuItem;
import com.senocular.utils.SWFReader;

var swfReader:SWFReader = new SWFReader(root.loaderInfo.bytes);
var menuItemLabel:String = "SWF Publish date: "+ getSwfModificationDate(swfReader);
var cm:ContextMenu = new ContextMenu();
cm.hideBuiltInItems();
var cmi:ContextMenuItem = new ContextMenuItem(menuItemLabel);
cm.customItems.push(cmi);
this.contextMenu = cm;

function getSwfModificationDate($swfReader:SWFReader):String {
	var metadata:String = $swfReader.metadata;
	var swfMetadataArray:Array = metadata.split("xmp:ModifyDate>");
	var modDate:String = swfMetadataArray[1].substr(0, 19);
	var date:String = modDate.substr(0, 10);
	var time:String = modDate.substr(11, 8);
	return date + " " + time;
}

http://www.senocular.com/flash/actionscript/?file=ActionScript_3.0/com/senocular/utils/SWFReader.as

This code uses Senocular SWFReader class to get the modification (publish) date of the SWF, and then displays it as a right-click menu item. You need to make sure that your SWF includes the XMP metadata. In the Flash IDE you can turn this on by going to Publish Settings > Flash > Include XMP metadata.

AS3 Show SWF Publish Date and Time in Right-Click Menu

date

ActionScript 3