The ISO format allows times strung together without a demarcating ":", so make sure that these markers are now optional.
function prepareTime(format, loc, iso) {
    var timeSuffixMapping = {'h':0,'m':1,'s':2}, add;
    loc = loc || English;
    return format.replace(/{([a-z])}/g, function(full, token) {
      var separators = [],
          isHours = token === 'h',
          tokenIsRequired = isHours && !iso;
      if(token === 't') {
        return loc['ampm'].join('|');
      } else {
        if(isHours) {
          separators.push(':');
        }
        if(add = loc['timeSuffixes'][timeSuffixMapping[token]]) {
          separators.push(add + '\\s*');
        }
        return separators.length === 0 ? '' : '(?:' + separators.join('|') + ')' + (tokenIsRequired ? '' : '?');
      }
    });
  }