def time(unit=None):
    """
    Returns axis label for time with different units
    """
    if unit is None:
        unit='hour'
    unit=unit.lower()
    units={
        'second':'s',
        'seconds':'s',
        's':'s',
        #
        'hour':'h',
        'hours':'h',
        'h':'h'
    }
    return f'Time/{units[unit]}'