The Israeli army forces carried out, on Saturday, a widespread military operation into the West Bank town of Jenin and its refugee camp, local Palestinian sources said.
The Israeli Army is active on weekends
Saturday is part of the weekend. I think the system got it wrong because I used unfamiliar phrasing
( z1 activity :ARG0 ( z2 military :name ( z3 name :op "Israeli" :op "Army" ) ) :time ( z4 weekend ) )