The very first rung, and its comment, do not go together. That alone could be causing the confusion.
The rung comment says to make an Array of 7 DINTs to hold the WallClock values returned by the GSV.
That is perfectly OK, and the GSV Instruction Help also suggests that you need a 7 DINT array....
Array[0] = Year
Array[1] = Month
Array[2] = Day
Array[3] = Hours
Array[4] = Minutes
Array[5] = Seconds
Array[6] = uSeconds
However, the destination they show in the GSV instruction itself is Wall_Clock.Year. That is clearly NOT an array element.
What they have done is to use a common trick to help with the identification of the data fields that GSVs and SSVs use. In employing this "trick" they have forgotten to update the rung comment.
The trick is to create a UDT that has the same size/shape as the 7 DINT array. In this case they have made a UDT with 7 DINT members. This maintains the size/shape of the receiving "block", and the GSV happily writes the data into the User-Defined tag.
Their UDT will have the following members, all of DINT data-type, and order is important.....
.Year
.Month
.Day
.Hours
.Mins
.Secs
.MicroSecs