How to specify the timestamp for a snapshot version

Usually we specify the SNAPSHOT version to get the latest jars. For example,
  <dependencies>

    <dependency>
      <groupId>exa</groupId>
      <type>jar</type>
      <artifactId>app-mbeans-core</artifactId>
      <version> 3.3.0-SNAPSHOT</version>
    </dependency>
   
  </dependencies>

But if we want to use one old SNAPSHOT version via timestamp, it is as follows:
  <dependencies>

    <dependency>
      <groupId>exa</groupId>
      <type>jar</type>
      <artifactId>app-mbeans-core</artifactId>
      <version> 3.3.0-20111028.094530-5</version>
    </dependency>
   
  </dependencies>