# sdate - Eternal September Date
  #
  # date -d '1993-09-01 UTC 8130 days'
  #
  # ce: .mshell;
  #
  s=`date --date="1993-09-01 UTC" +%s`
  if [ -z $1 ]; then
    n=`date +%s`
  else
    n=`date --date="$1" +%s`
  fi
  d=`expr \( $n - $s \) / 86400 + 1`
  if [ $d -ge 1 ]; then
    echo September $d, 1993
  else
    echo Error: date not in Eternal September epoch
  fi

And today is:

September 8153, 1993

Yes, I mourn the internet.