NASA has been watching the 6-ton (5.4-metric ton) satellite closely. On Friday officials moved up their prediction for its arrival to Sept. 23, give or take a day.
(From NASA: Satellite pieces to hit Earth in a week - Yahoo! News)
Does Sept. 23, give or take a day mean September 23, or a day before/after that day?
Merriam-Webster's Learner's Dictionary
He ran a mile, give or take a few yards.
It'd be okay to say "give or take a few yards either way" instead, wouldn't it?
The movie lasted three hours, give or take a few minutes either way.
It'd be okay to say "give or take a few minutes" instead, wouldn't it?
To me it's redundant to say bot "give or take" and "either way". Giving and taking tells you that the figure given may be modified slightly "either way."