Beamer: How to disable/delete author's name at first slide, and move date to the end of slide

Question

This is my latex beamer content:

\documentclass[11pt]{beamer}
\usetheme{Warsaw}
\usepackage[utf8]{inputenc}
\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{graphicx}
\graphicspath{ {images/} }
\usepackage[utf8]{vietnam}
\author{author name}
\title{Xây dựng website nộp đồ án}
%\setbeamercovered{transparent} 
%\setbeamertemplate{navigation symbols}{} 
%\logo{} 
%\institute{} 
%\date{} 
%\subject{} 

% Page number
\addtobeamertemplate{navigation symbols}{}{%
    \usebeamerfont{footline}%
    \usebeamercolor[fg]{footline}%
    \hspace{1em}%
    Slide \insertframenumber / \inserttotalframenumber
}

\begin{document}

% Slide 01
\begin{frame}
\titlepage
\begin{tabbing}
\hspace{10em}\=\kill
Mentor: \> Dr. ABC EFG \\ 
Student: \> EFG CBA \\ 
Class: \> ZYW
\end{tabbing} 

\end{frame}

result:

Please help me:

1. Move "Ngày 22 tháng 1 năm 2015" (date) to the end of frame.
   
2. Hide/(or disable) author name at first slide.
   Thank you!

Answer 1

For the author as a quick hack: use \author[author name]{}

Edit: For the date, you could use \date[\today]{} in the preamble and then add the date manually (with \today) at the bottom of your slide - simply below the mentor, student etc.

maybe also the suggestions in here help.