# File lib/time.rb, line 444
  def xmlschema(fraction_digits=0)
    sprintf('%d-%02d-%02dT%02d:%02d:%02d',
      year, mon, day, hour, min, sec) +
    if fraction_digits == 0
      ''
    elsif fraction_digits <= 6
      '.' + sprintf('%06d', usec)[0, fraction_digits]
    else
      '.' + sprintf('%06d', usec) + '0' * (fraction_digits - 6)
    end +
    if utc?
      'Z'
    else
      off = utc_offset
      sign = off < 0 ? '-' : '+'
      sprintf('%s%02d:%02d', sign, *(off.abs / 60).divmod(60))
    end
  end