def _get_min_overlap_timestamp(df1_timestamps, df2_timestamps):
    """
    Get the minimum overlapping timestamp from two series
    """
    if df1_timestamps.max() < df2_timestamps.min() or df1_timestamps.min(
        ) > df2_timestamps.max():
        raise IndexError(
            'No overlapping data. Ranges: {0} to {1}  and {2} to {3}'.
            format(df1_timestamps.min(), df1_timestamps.max(),
            df2_timestamps.min(), df2_timestamps.max()))
    return max(df1_timestamps.min(), df2_timestamps.min())
