def _calculate_bins(self, data: DataFrame) -> np.ndarray:
"""Calculate bins given data"""
values = data._convert(datetime=True)._get_numeric_data()
values = np.ravel(values)
values = values[~isna(values)]
hist, bins = np.histogram(
values, bins=self.bins, range=self.kwds.get("range", None)
)
return bins
