How does bitcoin block halving work?

[doublemore]

So like first halving was 2013, shouldnt the 2nd be in 2017, i thought it was every 4 years without fail:




Then some people are saying its going to be june 2016, WTF? thats great indeed but how can it change.  

If it can change how can we trust bitcoin that future block halvings aren't like every 1 month or something?

[NeuroticFish]

Halving happens at certain block numbers. So the moment in time depends on the global hash rate and cannot be known very accurate.

[odolvlobo]

The subsidy halves after every 210,000 blocks (see the bottom axis). That takes approximately 4 years.

[BlackSpidy]

Yeah, it halves every certain amount of blocks, which are not mined at a constant rate. Hash power and the network's adjustment of difficulty can contribute to the halving being a bit "early" or "late" on that 4-year schedule.

[Amph]

2013? i remember that the first halving was around the end of november, the controlled supply report 11-28-2012

that chart did not say 2013 at all, notice how the red line(inflation) start to fall before 2013...

however the next halving will be early, because miners are actually mining more coins than expected, this is due to the diff retarget and the bigger hash that keep increasing at a much faster rate in comparison with the old days

[doublemore]

ok thanks all.

2013? i remember that the first halving was around the end of november, the controlled supply report 11-28-2012

that chart did not say 2013 at all, notice how the red line(inflation) start to fall before 2013...

however the next halving will be early, because miners are actually mining more coins than expected, this is due to the diff retarget and the bigger hash that keep increasing at a much faster rate in comparison with the old days

Can miners speed things up by much more then? could we ever see block halving at 3 or even every 2 years for example?

[Amph]

ok thanks all.

2013? i remember that the first halving was around the end of november, the controlled supply report 11-28-2012

that chart did not say 2013 at all, notice how the red line(inflation) start to fall before 2013...

however the next halving will be early, because miners are actually mining more coins than expected, this is due to the diff retarget and the bigger hash that keep increasing at a much faster rate in comparison with the old days

Can miners speed things up by much more then? could we ever see block halving at 3 or even every 2 years for example?

i don't think the difference is not so big, we are talking about 200 more coins per day, so around 73k more per year, 300k in 4 year, talking about % would be 6% more coins with the current reward over 4 years

so around 1-2 months early at best

[arallmuus]

Can miners speed things up by much more then? could we ever see block halving at 3 or even every 2 years for example?

Yes they can. Due to that difficulty is updated every 2106 blocks (14 days approximately) , this means that if the hashrate increase before the next difficulty adjustment then the number of blocks found will be higher than expected and difficulty readjustment will be faster than 14 days

You should take into account that it is 10 minutes/block which means that it is 6 blocks for 1 hour and approximately

144 blocks / day .

144 blocks x 365 = 52560

Halvings occur every 210,000 blocks or merely 4 years (rough count) so :

52650 x 4 = 210,240 blocks approximately 4 years as per calculations


This is an old excel from reddit that pinpoint few difficulty readjustment and the data was taken from last halving until June, 18 2014. Data shows that we are already 103 days earlier than expected



P.S : couldnt find the newest data regarding this, will be glad if there is someone who can share about this