def METHOD_NAME(df: pd.DataFrame, column_name: Hashable) -> pd.DataFrame:
    """Convert unix epoch time into Python datetime format.
    Note that this ignores local tz and convert all timestamps to naive
    datetime based on UTC!
    This method mutates the original DataFrame.
    Examples:
        >>> import pandas as pd
        >>> import janitor
        >>> df = pd.DataFrame({"date": [1651510462, 53394822, 1126233195]})
        >>> df
                 date
        0  1651510462
        1    53394822
        2  1126233195
        >>> df.convert_unix_date('date')
                         date
        0 2022-05-02 16:54:22
        1 1971-09-10 23:53:42
        2 2005-09-09 02:33:15
    Args:
        df: A pandas DataFrame.
        column_name: A column name.
    Returns:
        A pandas DataFrame with corrected dates.
    """
    try:
        df[column_name] = pd.to_datetime(df[column_name], unit="s")
    except OutOfBoundsDatetime:  # Indicates time is in milliseconds.
        df[column_name] = pd.to_datetime(df[column_name], unit="ms")
    return df