from datetime import datetime


def milliseconds_to_datetime(milliseconds):
    """Convert a timestamp in milliseconds to a :class:`~datetime.datetime`.

    Parameters
    ----------
    milliseconds : :class:`int`
        A timestamp in milliseconds.

    Returns
    -------
    :class:`~datetime.datetime`
        The `milliseconds` converted to a :class:`~datetime.datetime` object.
    """
    return datetime.fromtimestamp(milliseconds * 1e-3)