def time_to_decimal(time):
    """
    Get the decimal part of a date.

    Parameters
    ----------
    time : array
        a time with hms format split by ':'

    Returns
    -------
    decimal_time : string
        the decimal part of a date.

    Examples
    --------
    >>> time = [20, 17, 40.088]
    >>> time_to_decimal(time)
    '73040'
    """
    return str(int(time[0]) * 3600 + int(time[1]) * 60 + int(time[0]))