James, it is possible. I did it when I first added the feature as I approached previous customers to add a review and I didn't want a bunch of reviews dated the same day with nothing either side--looks fishy.
I removed the date, but now several months later, I want to add it back, and don't remember how I removed it and can't find any reference to adding it back!
If you have learned in the meantime how to remove it, I would love to hear how, so I can add it back.
Thanks!