How do I build this JSON in a function node?

Third party integrations Node-RED
3

You were pretty close. Just remove the data stuff from your call-service node and put this in your function node.

var MasterBedroom = [10622,28695,16522,35895];
var LaundryRoom = [10948,25347,16498,28597];
var BreakfastNook = [16523,26953,20923,31403];
var Kitchen = [17905,22410,20505,26760];
var LisasOffice = [17220,17547,21320,22497];
var LivingRoom = [20649,24065,26149,30365];
var Foyer = [21225,20361,23675,24061];
var StevesOffice = [23705,20103,30455,23753];
var Hallway = [26010,23831,27310,30681];
var KidsBathroom = [27221,23694,30771,25344];
var AshleysBedroom = [27226,25345,31726,29595];
var MarksBedroom = [26033,29634,30183,35034];
msg.payload = {
    data: {
        repeats: 1,
        zone: MarksBedroom
    }
}

return msg;