It is timely to remember, with respect to genocide, that this year, in 1998, we will be celebrating not only the anniversary of the Universal Declaration of Human Rights, but also the 50th anniversary of the Convention on the Prevention and Punishment of the Crime of Genocide that was breached by individuals in Bosnia-Hercegovina, as the International Crime tribunal will show, if it can bring to justice the individuals charged with such crimes.
the Convention on the Prevention and Punishment of the Crime of Genocide was first published in 1948
The context states that in 1998 the Convention on the Prevention and Punishment of the Crime of Genocide celebrated its 50th anniversary, so it must have been created 50 years prior - aka 1948. The system could likely not apply the logic needed to understand a 50th anniversary meant 50 years ago, and then to take 50 years off the year 1998. 
( z1 publish :ARG1 ( z2 treaty :name ( z3 name :op "Convention" :op "on" :op "Prevention" :op "and" :op "Punishment" :op "of" :op "the" :op "Crime" :op "of" :op "Genocide" ) ) :ord ( z4 ordinal-entity :value 1 ) :time ( z5 date-entity :year 1948 ) )