it's in the code (along with a blocksize increase)

https://github.com/zcoinofficial/zcoin/commit/4ab72aa04249ec05b72c9f1af61d14de2d905e06#diff-e8db9b851adc2422aadfffca88f14c91R76

... aka about 5000 blocks from now, on 2017 July 27 give or take a day