'Convert times to strings, using signed 5 digit if necessary.'

@property
def value(self):

    if (u'long' not in self.out_subfmt):
        jd = (self.jd1 + self.jd2)
        if ((jd.min() < 1721425.5) or (jd.max() >= 5373484.5)):
            self.out_subfmt = (u'long' + self.out_subfmt)
    return super(TimeFITS, self).value
