Monday
Monday thru Sunday !
Monday begins the week. Say you went Monday, the soonest you can go in for the second donation is Thursday. There is a 48 hour wait till you can donate again, but you are only allowed two donations a week. Say you went Monday and waited till Sunday for your second donation, then when the new week starts, your earliest first donation of the new week gets pushed from Monday to Wednesday because of the 48 hour wait after Sundays second donation.
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