from datetime import datetime


def add_date_to_filename(filename):
    """
    Add current date to a filename.

    Args:
        filename (str)
    Returns:
        new_filename (str):
            filename with added date.
    """
    now = datetime.now()
    # dd/mm/YY H:M:S
    dt_string = now.strftime("%d-%m-%Y_%H:%M")
    new_filename = '_'.join([filename, dt_string])

    return new_filename