title: Get Yesterday's date in solaris
body: <p>I am running SunOS.</p>
  
  <pre><code>bash-3.00$ uname -a
  SunOS lvsaishdc3in0001 5.10 Generic_142901-02 i86pc i386 i86pc
  </code></pre>
  
  <p>I need to find <code>Yesterday's date in linux</code> with the proper formatting passed from command prompt. When I tried like this on my shell prompt-</p>
  
  <pre><code>bash-3.00$ date --date='yesterday' '+%Y%m%d'
  date: illegal option -- date=yesterday
  usage:  date [-u] mmddHHMM[[cc]yy][.SS]
          date [-u] [+format]
          date -a [-]sss[.fff]
  </code></pre>
  
  <p>I always get date <code>illegal option</code>, why is it so?
  Is there anything wrong I am doing?</p>
  
  <p><strong>Update:-</strong></p>
  
  <pre><code>bash-3.00$ date --version
  date: illegal option -- version
  usage:  date [-u] mmddHHMM[[cc]yy][.SS]
          date [-u] [+format]
          date -a [-]sss[.fff]
  </code></pre>