I heard it upcoming 1 day only double points too.
The best deal so far as long as I know is Saks if you are Platinum or Diamond.
If so, Saks gives you 6 points per $1.($258 gift card value for $4300)
On Double Points Days, 12 points per $1.($516 gift card value for $4300)
Triple Point Days, 18 points per $1. ($774 gift card value for $4300)
For Incircle members,
NM gives you only 2 points per $1.
If you are President Circle(Already spent more than $75,000 this year) then 5 points per $1.
You can pick up any 1 day to double it if you already spent more than $2500 on Neiman Card.
NM sometimes does special gift card event in store, but Chanel hardly participates in it.