In cases like this, a large portion of the "money" paid is actually in the form of shares, which can vary wildly on a day-to-day basis (especially during a takeover!). It doesn't make sense to specify the value of it too precisely because nobody knows what the shares are going to be worth tomorrow.
That's a good reason for the press to round such figures, but the actual figure is round, on the day it was decided, and that itself is mysterious.
If it's worth saying, but not worth its own post (even in Discussion), then it goes here.
Duration set to six days to encourage Monday as first day.