I personally detest calendars which display Sunday as the first day of the week, since it&#x27;s incorrect according to one of the earliest memories I have -- my mum teaching my this rhyme:<p><pre><code>  Solomon Grundy,
  Born on a Monday,
  Christened on Tuesday,
  Married on Wednesday,
  Took ill on Thursday,
  Grew worse on Friday,
  Died on Saturday,
  Buried on Sunday,
  That was the end,
  Of Solomon Grundy.
</code></pre>
Also, Saturday and Sunday are the week<i>end</i>, not the week-edges.<p>--<p>There&#x27;s a bug in cal -- the man page says &quot;-M&quot; makes the week start on Monday, but my version doesn&#x27;t accepthe argument.<p>I find it quite confusing when calendars mess this up.  I once booked a flight on the wrong day, because I somehow switched to the American localization of the airline&#x27;s website part-way through the booking process.