def _to_m8(key, tz=None):
    if not isinstance(key, Timestamp):
        # this also converts strings
        key = Timestamp(key, tz=tz)

    return np.int64(tslib.pydt_to_i8(key)).view(_NS_DTYPE)
Return the value to use when the specified columns are dragged or
dataset/ETHPy150Open pydata/pandas/pandas/tseries/index.py/_to_m8--crossover with--dataset/ETHPy150Open enthought/pyface/pyface/ui/wx/grid/simple_grid_model.py/SimpleGridModel.get_cols_drag_value