Table with header cells in the top row and first column

For this type of table, you can use <thead> to identify header rows and @rowheader to identify a header column.

Table 1. Example: Bus Timetable
Monday Tuesday Wednesday Thursday Friday
09:00 - 11:00 Closed Open Open Closed Closed
11:00 - 13:00 Open Open Closed Closed Closed
13:00 - 15:00 Open Open Open Closed Closed
15:00 - 17:00 Closed Closed Closed Open Open 
<table id="table_dqk_n24_vdb" rowheader="firstcol">
   <title>Example: Bus Timetable</title>
   <tgroup cols="6">
     <colspec colnum="1" colname="col1"/>
     <colspec colnum="2" colname="col2"/>
     <colspec colnum="3" colname="col3"/>
     <colspec colnum="4" colname="col4"/>
     <colspec colnum="5" colname="col5"/>
     <colspec colnum="6" colname="col6"/>
     <thead>
       <row>
        <entry/>
        <entry>Monday</entry>
        <entry>Tuesday</entry>
        <entry>Wednesday</entry>
        <entry>Thursday</entry>
        <entry>Friday</entry>
       </row>
     </thead>
     <tbody>
      <row>
        <entry>09:00 - 11:00</entry>
        <entry>Closed</entry>
        <entry>Open</entry>
        <entry>Open</entry>
        <entry>Closed</entry>
        <entry>Closed</entry>
      </row>
      <row>
        <entry>11:00 - 13:00</entry>
        <entry>Open</entry>
        <entry>Open</entry>
        <entry>Closed</entry>
        <entry>Closed</entry>
        <entry>Closed</entry>
      </row>
      <row>
        <entry>13:00 - 15:00</entry>
        <entry>Open</entry>
        <entry>Open</entry>
        <entry>Open</entry>
        <entry>Closed</entry>
        <entry>Closed</entry>
      </row>
      <row>
        <entry>15:00 - 17:00</entry>
        <entry>Closed</entry>
        <entry>Closed</entry>
        <entry>Closed</entry>
        <entry>Open</entry>
        <entry>Open</entry>
      </row>
    </tbody>
  </tgroup>
</table>