/ find all the weekends for a given year

finddayofweek:{[x]
  numdays: x - `week$ x;
  vec:`mon`tues`wed`thurs`fri`sat`sun;
  vec[numdays]}

findfirstofmonth:{[year]
  mons: ("01";"02";"03";"04";"05";"06";"07";"08";"09";"10";"11";"12");
  firsts: "D"$' (string year) ,/: (mons) ,\: ("01");
  :firsts,'finddayofweek each firsts
  }

year: "I"$ .z.x[0]

show findfirstofmonth[year]