Auckland Cups

[PeterLambFan]

It seems strange to me that the Auckland Cup for Harness is December 31st. The greyhound cup is at the end of January and the Galloping cup is in March. 
 

I am assuming they were all at a similar time of year at some point? What was the logic in splitting them up? 
 

I realise after this year the Greyhound Cup will be gone but it just seems odd as I’m sure they use to have a cup week of sorts a few year back.