user37587: When does the 2016 halving happen? Is it a predicted date or could it be when network load is achieved? 

user575: The exact time of the halving will be unknown until it happens.
The most significant factor in the uncertainty is the rate at which new hashrate will enter the network. If the hashrate increases, the halving will be sooner.
Statistical variance also plays a factor.
My paper Predicting Block Halving Party Times discusses some of the methods used to predict the time in advance.
Websites such as http://www.thehalvening.com/ give a rough estimate, which stands at July 10, 10:20 GMT at the time of this writing. New hashrate is likely to push this forward to July 8-9.

user33038: The 2016 halving, from 25 BTC to 12.5 BTC, happened on: Saturday July 9 2016 16:46:13 UTC.
The reward was halved in:


user36310: There is no precise time and date but July 10th or 11th is expected. The halving occurs every 210,000 blocks. The first time (block 210,000) the reward fell from 50 to 25 BTC. On block 420,000 it will fall from 25 to `12.5 btc

user5406: The first block with the halved block subsidy is 420,000. However, blocks are discovered in a random process – whereas the protocol aims to have blocks found approximately every ten minutes, in effect blocks are currently found about every 8.94 minutes. Therefore, one can only estimate the precise arrival of the Halving:

thehalvening.com estimates 2016-07-10 – 10:24 UTC  
bitcoinclock.com estimates 2016-07-10 – 05:39 UTC  
bitcoinblockhalf.com estimates 2016-07-10 – 10:10 UTC

It's not clear from the sites whether they rely on the current measured block interval or the theoretical ten minutes for their estimates. So far, it seems to me that the time has mostly been overestimated, earlier predictions were for later in July. 
It seems therefore likely to me that the halving will occur on the 8th, 9th or the 10th of July. Naturally, any predictions will increase in accuracy as the halving draws nearer.

37587: <p>When does the 2016 halving happen? Is it a predicted date or could it be when network load is achieved? </p>
 575: <p>The exact time of the halving will be unknown until it happens.</p>

<p>The most significant factor in the uncertainty is the rate at which new hashrate will enter the network. If the hashrate increases, the halving will be sooner.</p>

<p>Statistical variance also plays a factor.</p>

<p>My paper <a href="https://bitcoil.co.il/files/BlockParty.pdf" rel="nofollow">Predicting Block Halving Party Times</a> discusses some of the methods used to predict the time in advance.</p>

<p>Websites such as <a href="http://www.thehalvening.com/" rel="nofollow">http://www.thehalvening.com/</a> give a rough estimate, which stands at July 10, 10:20 GMT at the time of this writing. New hashrate is likely to push this forward to July 8-9.</p>
 33038: <p>The 2016 halving, from 25 BTC to 12.5 BTC, happened on: <strong>Saturday July 9 2016 16:46:13 UTC.</strong></p>

<p>The reward was <a href="https://blockchain.info/block/000000000000000002cce816c0ab2c5c269cb081896b7dcb34b8422d6b74ffa1" rel="nofollow noreferrer">halved in</a>:</p>

<p><a href="https://i.stack.imgur.com/I53vC.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/I53vC.png" alt="enter image description here"></a></p>
 36310: <p>There is no precise time and date but July 10th or 11th is expected. The halving occurs every 210,000 blocks. The first time (block 210,000) the reward fell from 50 to 25 BTC. On block 420,000 it will fall from 25 to `12.5 btc</p>
 5406: <p>The first block with the halved block subsidy is <code>420,000</code>. However, blocks are discovered in a random process – whereas the protocol aims to have blocks found approximately every ten minutes, in effect blocks are currently found <a href="https://blockchain.info/stats">about every 8.94 minutes</a>. Therefore, one can only estimate the precise arrival of the Halving:</p>

<ul>
<li><a href="http://www.thehalvening.com/#1">thehalvening.com</a> estimates 2016-07-10 – 10:24 UTC  </li>
<li><a href="http://bitcoinclock.com/">bitcoinclock.com</a> estimates 2016-07-10 – 05:39 UTC  </li>
<li><a href="http://www.bitcoinblockhalf.com/">bitcoinblockhalf.com</a> estimates 2016-07-10 – 10:10 UTC</li>
</ul>

<p>It's not clear from the sites whether they rely on the current measured block interval or the theoretical ten minutes for their estimates. So far, it seems to me that the time has mostly been overestimated, earlier predictions were for later in July. </p>

<p>It seems therefore likely to me that the halving will occur on the <strong>8th, 9th or the 10th of July</strong>. Naturally, any predictions will increase in accuracy as the halving draws nearer.</p>
