date_diff() output?

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<process version="5.1.001">
  <context>
    <input/>
    <output/>
    <macros/>
  </context>
  <operator activated="true" class="process" compatibility="5.1.001" expanded="true" name="Process">
    <process expanded="true" height="341" width="815">
      <operator activated="true" class="generate_data" compatibility="5.1.001" expanded="true" height="60" name="Generate Data" width="90" x="45" y="75">
        <parameter key="number_examples" value="10"/>
      </operator>
      <operator activated="true" class="select_attributes" compatibility="5.1.001" expanded="true" height="76" name="Select Attributes" width="90" x="179" y="75">
        <parameter key="invert_selection" value="true"/>
        <parameter key="include_special_attributes" value="true"/>
      </operator>
      <operator activated="true" class="generate_attributes" compatibility="5.1.001" expanded="true" height="76" name="Generate Attributes" width="90" x="313" y="75">
        <list key="function_descriptions">
          <parameter key="Now" value="date_now()"/>
        </list>
      </operator>
      <operator activated="true" class="delay" compatibility="5.1.001" expanded="true" height="76" name="Delay" width="90" x="447" y="75">
        <parameter key="delay" value="fixed"/>
        <parameter key="delay_amount" value="1234"/>
      </operator>
      <operator activated="true" class="generate_attributes" compatibility="5.1.001" expanded="true" height="76" name="Generate Attributes (2)" width="90" x="581" y="75">
        <list key="function_descriptions">
          <parameter key="NowPlus" value="date_now()"/>
          <parameter key="diff" value="date_diff(Now,NowPlus)"/>
        </list>
      </operator>
      <connect from_op="Generate Data" from_port="output" to_op="Select Attributes" to_port="example set input"/>
      <connect from_op="Select Attributes" from_port="example set output" to_op="Generate Attributes" to_port="example set input"/>
      <connect from_op="Generate Attributes" from_port="example set output" to_op="Delay" to_port="through 1"/>
      <connect from_op="Delay" from_port="through 1" to_op="Generate Attributes (2)" to_port="example set input"/>
      <connect from_op="Generate Attributes (2)" from_port="example set output" to_port="result 1"/>
      <portSpacing port="source_input 1" spacing="0"/>
      <portSpacing port="sink_result 1" spacing="0"/>
      <portSpacing port="sink_result 2" spacing="0"/>
    </process>
  </operator>
</process>