IF Formula to show only last 6 results

Morning guys,

I am having a bit of brain cramp trying to set up part of a league spreadsheet that will just show the last 6 game week results.

At 1st glance it may seem to be a simple IF formula, however, game weeks are not always 7 days apart, neither do they have exactly 42 days between the six relevant game week spreads so an IF statement IF(GW?>42," ",GW?,IF(GW?>35," ",GW? and so on doesn't cut it.
The sample has been set up to show what and where the results should be, the formulas to return Win, Loss, & Draw results are already in place (in the actual workbook) but I have added a few formulas as reference points to show the number of days between three different variables.

Bottom line for the requirements are, at season start show the 1st 6 weeks results, at GW 7 start clear GW 1 and show GW 2 thru 7, and so on until the last 6 weeks of the season where the results would be static.

I am going round in circles, getting the formula to work, I can get it for a few weeks then the formula fails and I need to start all over again.

Hopefully I can get some advice from you chaps because I may be over thinking this.