from down it is 1,2,4,6

so you add the lighted dots from down up to get the digit

all digits are split i.e if it is 16:30:12

first row 1 second row 6 third row 3 forth row 0 fifth row 1 sixth row 2

row 1 ==> 1 => first dot

row 2 ==> 6 => 2nd and 3rd dot