Was wondering if someone could explain what Day Landing Distance means in the aerodrome data section of a vta/vnc legend?

It shows : DAYS 60 Day Landing Distance

It is there for airports that have runways that are different lengths during the day versus the night.

In your example your runway is 6000 feet long during the day. At night it might only be 1500 feet long as that is all they put in for runway lights, some places have a shorter runway at night to ensure a safe approach path.

So if you see DAYS XX it simply means the runway length shown applies for daytime only.

thanks, makes sense now.