http://www.symfony-project.org/forum/index.php/m/20339/

> where did you find that 'p' option? is this php specific or a symfony thing?

It's a Symfony thing in sfDateFormat::getPattern().

switch ($pattern)
{
  case 'd':
    return $this->formatInfo->ShortDatePattern;
    break;
  case 'D':
    return $this->formatInfo->LongDatePattern;
    break;
  case 'p':
    return $this->formatInfo->MediumDatePattern;
    break;
  case 'P':
    return $this->formatInfo->FullDatePattern;
    break;
  case 't':
    return $this->formatInfo->ShortTimePattern;
    break;
  case 'T':
    return $this->formatInfo->LongTimePattern;
    break;
  case 'q':
    return $this->formatInfo->MediumTimePattern;
    break;
  case 'Q':
    return $this->formatInfo->FullTimePattern;
    break;
  case 'f':
    return $this->formatInfo->formatDateTime($this->formatInfo->LongDatePattern, $this->formatInfo->ShortTimePattern);
    break;
  case 'F':
    return $this->formatInfo->formatDateTime($this->formatInfo->LongDatePattern, $this->formatInfo->LongTimePattern);
    break;
  case 'g':
    return $this->formatInfo->formatDateTime($this->formatInfo->ShortDatePattern, $this->formatInfo->ShortTimePattern);
    break;
  case 'G':
    return $this->formatInfo->formatDateTime($this->formatInfo->ShortDatePattern, $this->formatInfo->LongTimePattern);
    break;
  case 'i':
    return 'yyyy-MM-dd';
    break;
  case 'I':
    return 'yyyy-MM-dd HH:mm:ss';
    break;
  case 'M':
  case 'm':
    return 'MMMM dd';
    break;
  case 'R':
  case 'r':
    return 'EEE, dd MMM yyyy HH:mm:ss';
    break;
  case 's':
    return 'yyyy-MM-ddTHH:mm:ss';
    break;
  case 'u':
    return 'yyyy-MM-dd HH:mm:ss z';
    break;
  case 'U':
    return 'EEEE dd MMMM yyyy HH:mm:ss';
    break;
  case 'Y':
  case 'y':
    return 'yyyy MMMM';
    break;
  default :
    return $pattern;
}

The top ones use your locale to determine the formatting.

documented on: 24 January 2007, mikenolan