First of all, I would turn the date field into number in the script using the num function so it's not that heavy in memory if you haven't already.
num(date#([Target Date], 'DD/MM/YYYY'))
I would define a couple variables for that so you can use them easily in the set analysis.
I'm considering that you want to calculate Target Dates that are > than 6 months from today's / reload date.
The first one would be:
vTargetDate6M Definition: = addmonths(floor(num(ReloadTime()), 6) This variable will contain the date that is exactly 6 months away from the latest Reload date. You can use Today() instead if you want to see against Today's date.