How to use the ephem.date function in ephem

if opt.schedule:
                    d = sat_rise.tuple()
                    rise_time = "%04d%02d%02d_%02d%02d" % (d[0], d[1], d[2], d[3], d[4])

                    offset_rise = ephem.date(sat_rise - ephem.minute)
                    d = offset_rise.tuple()
                    offset_rise_time = "%04d-%02d-%02dT%02d:%02d:%02dZ" % (
                        d[0],
                        d[1],
                        d[2],
                        d[3],
                        d[4],
                        int(d[5]),
                    )

                    offset_set = ephem.date(sat_set + ephem.minute)
                    d = offset_set.tuple()
                    offset_set_time = "%04d-%02d-%02dT%02d:%02d:%02dZ" % (
                        d[0],
                        d[1],
                        d[2],
                        d[3],
                        d[4],
                        int(d[5]),
                    )

                    cmd_lines = []
                    radio_channel = string.split(site["radio"]["channel"][1:-1], ",")
                    radio_gain = string.split(site["radio"]["gain"][1:-1], ",")
                    radio_address = string.split(site["radio"]["address"][1:-1], ",")
                    recorder_channels = string.split(
                        site["recorder"]["channels"][1:-1], ","

def gregorian_to_jd(greg):
    """
    Convert gregorian date in format YYYY/MM/DD HH:MM:SS.SS to JD
    """
    date = ephem.date(greg)
    jd = date + 2415020.
    return jd

def juldate2ephem(self, num):
        """
        Convert Julian date to ephem date, measured from noon, Dec. 31, 1899.

        Args:
            num: Julian date

        Returns:
            ephem date, measured from noon, Dec. 31, 1899.
        """
        return ephem.date(num - 2415020.)

def update_mjd(self, mjd):
        """
        observer : ephem.Observer object
        """

        self.observer.date = ephem.date(time.Time(mjd, format='mjd').datetime)

        self.altitudes_rad = []
        self.azimuth_rad = []
        self.eclip = []
        for sat in self.sat_list:
            try:
                sat.compute(self.observer)
            except ValueError:
                self.advance_epoch()
                sat.compute(self.observer)
            self.altitudes_rad.append(sat.alt)
            self.azimuth_rad.append(sat.az)
            self.eclip.append(sat.eclipsed)

        self.altitudes_rad = np.array(self.altitudes_rad)
        self.azimuth_rad = np.array(self.azimuth_rad)

def juldate2ephem(num):
    """Convert Julian date to an ephem date, which is measured from noon,
    Jan. 1, 1900."""
    return ephem.date(num - 2415020)

def juldate2ephem(num):
    """Convert Julian date to an ephem date, which is measured from noon,
    Jan. 1, 1900."""
    return ephem.date(num - 2415020)

def juldate2ephem(num):
    """Convert Julian date to ephem date, measured from noon, Dec. 31, 1899."""
    return ephem.date(num - 2415020.)

def mouseReleaseEvent(self, evt):
        if self.editing is not None:
            rect = self.rx[self.editing].rect()
            pos = evt.pos()
            self.rx[self.editing].setRect(rect.x(), rect.y(), rect.width(), pos.y()-rect.y()+ self.verticalScrollBar().value())
            rect = self.rx[self.editing].rect()
            
            print 'release', self.rx[self.editing].rect()
            if rect.height() / self.scale_y > 0.1:
                print 'Start time', str(ephem.date(ephem.now() + ((rect.y() - self.orig_y) / self.scale_y) * ephem.minute))
                print 'Duration', rect.height() / self.scale_y
                print 'Centre Frequency', (rect.x() + rect.width()/2 - self.orig_x) / self.scale_x + (self.fx0 * 1e6)

                self.rx[self.editing].setParams(ephem.date(ephem.now() + ((rect.y() - self.orig_y) / self.scale_y) * ephem.minute),
                                                rect.height() / self.scale_y,
                                                (rect.x() + rect.width()/2 - self.orig_x) / self.scale_x + (self.fx0 * 1e6))

                for f in self.scene().items(rect):
                    print f
                    if isinstance(f, PlannerSat):
                        print f.name, f.mode, f.freq, f.params
                        self.rx[self.editing].addChannel(f.name, f.mode, f.freq, f.tle, f.params)
            else:
                self.rx[self.editing].hide()
                self.rx[self.editing] = None
                self.rx = self.rx[:-1]
                self.editing = None
	else:
	    QtGui.QGraphicsView.mouseReleaseEvent(self, evt)
	    #QtCore.QEvent.ignore(evt)

if len(sys.argv) > 1 and sys.argv[1] == "-v":
        verbose = True
        sys.argv = sys.argv[1:]

    if len(sys.argv) > 1 and sys.argv[1] == "-c":
        output_format = "csv"
        sys.argv = sys.argv[1:]
    elif len(sys.argv) > 1 and sys.argv[1] == "-s":
        output_format = "sql"
        sys.argv = sys.argv[1:]
    else:
        output_format = "text"

    if len(sys.argv) > 1:
        start = ephem.date(sys.argv[1])
    else:
        start = ephem.date('2014/8/15 04:00')
    if len(sys.argv) > 2:
        end = ephem.date(sys.argv[2])
    else:
        end = ephem.date('2017/1/1')

    # Loop from start date to end date,
    # using a time of 10pm MST, which is 4am GMT the following day.
    # end = ephem.date('2016/1/1')
    # For testing, this spans a Mars/Moon/Venus conjunction:
    # d = ephem.date('2015/2/10 04:00')
    # end = ephem.date('2015/3/10')

    observer = ephem.Observer()
    observer.name = "Los Alamos"