time_string Function

    character(19) function time_string()
        implicit none
        character(10) :: data, time
        call date_and_time(data, time)
        time_string = data(1:4)//'-'//data(5:6)//'-'//data(7:8)//' '//time(1:2) &
                      //':'//time(3:4)//':'//time(5:6)
    end function time_string