def frontiers_from_bar_to_time(seq, bars):
    """
    Converts the frontiers (or a sequence of integers) from bar indexes to absolute times of the bars.
    The frontier is considered as the end of the bar.

    Parameters
    ----------
    seq : list of integers
        The frontiers, in bar indexes.
    bars : list of tuple of floats
        The bars, as (start time, end time) tuples.

    Returns
    -------
    to_return : list of float
        The frontiers, converted in time (from bar indexes).

    """
    to_return = []
    for frontier in seq:
        bar_frontier = bars[frontier][1]
        if bar_frontier not in to_return:
            to_return.append(bar_frontier)
    return to_return