This block time is not constant.  It is long and short depending the mining situation.   It resets because long period of long mining block time longer than targeted 1 minute per block after big ASIC miners left.

Overall the mining block time is close to 1 minute.  From beginning of coin genesis time to now,  345 days,  total of 706174 blocks. Did a math, roughly  40 seconds per block. Off by 40%, but not dramatically different.

The faster the blocktime,  then the quicker to get mining reward half event.  Originally the half will happen in 4 years, but 40 seconds per block, we get half in less than 3 years in stead of 4 years.