While certain days and hours historically showed lower average returns (making them potentially better for DCA purchases), the lack of statistical significance and period-to-period consistency suggests that strictly timing DCA purchases to specific days or hours is unlikely to yield consistently better results than a random approach.
Discussion
Interesting that Wednesday actually showed the lowest returns. I actually worry less about having the ability to move my own purchases (i.e. timing the market) than a big retail adoption of direct deposit DCA that creates a system that benefits the day traders and disadvantages the folks who want to have set and forget savings.
Good to see there isn't any evidence that we are there yet