I remembered it was discussed months ago and maybe longer in the past too.
Here is it:
https://bitcointalksearch.org/topic/--5403419It's just because of the average they use to calculate and the project they make between difficulties.
But I still think those will be a bit more accurate than the previous ones, the difficulty jumps are not the same as before and they really can't go anymore over 20-30% like years ago, the shear amount of gear that needs to do so is just impossible to come by.
From June till now the clocks have moved around 4-10 days, so probably with what is left the current times are less than one week off.
It is better to estimate according to the blocks, because an attempt to estimate the days may give a margin of error of about a month,
The estimate is done according to the current block time and the average between them, then simply transformed into days and months.
It's a pretty simple thing but since everyone likes different averages over different timespans, they do it just like a guy doing TA when they want to draw lines over periods of one year or one month, arbitrarily choosing dates, and thus having the same accuracy as TA..which we all know how it ends.
Anyhow, I don't know what's so special about 384 days from now, OP could have waited a few weeks and created the topic when one of the dozen of clocks would have shown there is exactly one year left to the halving!