Convert the incoming string containing some date / time info into a
    datetime instance.

def date_convert(string, match, ymd=None, mdy=None, dmy=None,
        d_m_y=None, hms=None, am=None, tz=None, mm=None, dd=None):
    '''Convert the incoming string containing some date / time info into a
    datetime instance.
    '''
    groups = match.groups()
    time_only = False
    if mm and dd:
        y=datetime.today().year
        m=groups[mm]
        d=groups[dd]
    elif ymd is not None:
        y, m, d = re.split(r'[-/\s]', groups[ymd])
    elif mdy is not None:
        m, d, y = re.split(r'[-/\s]', groups[mdy])
    elif dmy is not None:
        d, m, y = re.split(r'[-/\s]', groups[dmy])
    elif d_m_y is not None:
        d, m, y = d_m_y
        d = groups[d]
        m = groups[m]
        y = groups[y]
    else:
        time_only = True

    H = M = S = u = 0
    if hms is not None and groups[hms]:
        t = groups[hms].split(':')
        if len(t) == 2:
            H, M = t
        else:
            H, M, S = t
            if '.' in S:
                S, u = S.split('.')
                u = int(float('.' + u) * 1000000)
            S = int(S)
        H = int(H)
        M = int(M)

    if am is not None:
        am = groups[am]
        if am:
            am = am.strip()
        if am == 'AM' and H == 12:
            # correction for "12" hour functioning as "0" hour: 12:15 AM = 00:15 by 24 hr clock
            H -= 12
        elif am == 'PM' and H == 12:
            # no correction needed: 12PM is midday, 12:00 by 24 hour clock
            pass
        elif am == 'PM':
            H += 12

    if tz is not None:
        tz = groups[tz]
    if tz == 'Z':
        tz = FixedTzOffset(0, 'UTC')
    elif tz:
        tz = tz.strip()
        if tz.isupper():
            # TODO use the awesome python TZ module?
            pass
        else:
            sign = tz[0]
            if ':' in tz:
                tzh, tzm = tz[1:].split(':')
            elif len(tz) == 4:  # 'snnn'
                tzh, tzm = tz[1], tz[2:4]
            else:
                tzh, tzm = tz[1:3], tz[3:5]
            offset = int(tzm) + int(tzh) * 60
            if sign == '-':
                offset = -offset
            tz = FixedTzOffset(offset, tz)

    if time_only:
        d = time(H, M, S, u, tzinfo=tz)
    else:
        y = int(y)
        if m.isdigit():
            m = int(m)
        else:
            m = MONTHS_MAP[m]
        d = int(d)
        d = datetime(y, m, d, H, M, S, u, tzinfo=tz)

    return d