How to use the sunpy.time.parse_time function in sunpy

def time_to_x(self, time):
        """ Return x-coordinate in spectrogram that corresponds to the
        passed datetime value.

        Parameters
        ----------
        time : parse_time compatible
            Datetime to find the x coordinate for.
        """
        # This is impossible for frequencies because that mapping
        # is not injective.
        time = parse_time(time)
        diff = time - self.start
        diff_s = SECONDS_PER_DAY * diff.days + diff.seconds
        result = diff_s // self.t_delt
        if 0 <= result <= self.shape[1]:
            return result
        raise ValueError("Out of range.")

try:
                start = parse_time(start)
            except ValueError:
                # XXX: We could do better than that.
                if get_day(self.start) != get_day(self.end):
                    raise TypeError(
                        "Time ambiguous because data spans over more than one day"
                    )
                start = datetime.datetime(
                    self.start.year, self.start.month, self.start.day,
                    *map(int, start.split(":"))
                )
            start = self.time_to_x(start)
        if end is not None:
            try:
                end = parse_time(end)
            except ValueError:
                if get_day(self.start) != get_day(self.end):
                    raise TypeError(
                        "Time ambiguous because data spans over more than one day"
                    )
                end = datetime.datetime(
                    self.start.year, self.start.month, self.start.day,
                    *map(int, end.split(":"))
                )
            end = self.time_to_x(end)
        return self[:, start:end]

def in_interval(self, start=None, end=None):
        """ Return part of spectrogram that lies in [start, end).

        Parameters
        ----------
        start : None or datetime or parse_time compatible string or time string
            Start time of the part of the spectrogram that is returned. If the
            measurement only spans over one day, a colon separated string
            representing the time can be passed.
        end : None or datetime or parse_time compatible string or time string
            See start.
        """
        if start is not None:
            try:
                start = parse_time(start)
            except ValueError:
                # XXX: We could do better than that.
                if get_day(self.start) != get_day(self.end):
                    raise TypeError(
                        "Time ambiguous because data spans over more than one day"
                    )
                start = datetime.datetime(
                    self.start.year, self.start.month, self.start.day,
                    *map(int, start.split(":"))
                )
            start = self.time_to_x(start)
        if end is not None:
            try:
                end = parse_time(end)
            except ValueError:
                if get_day(self.start) != get_day(self.end):