Setting a Scheduled Call to a Certain Time

I'm using the schedule call function for new leads, once a lead matching the criteria is created I want to schedule a call for users + 1 business day at 4:00 PM.

Currently when a new lead is created it schedules for 1 business day at the created time.

How do I change the script to addBusiness day at a specific time?

Thanks

leadDetails = zoho.crm.getRecordById("Leads",leadId);

createdtime = ifnull(leadDetails.get("Created_Time"),"").toTime("yyyy-MM-dd'T'HH:mm:ss").addBusinessDay(1);

mp = Map();

mp.put("Subject","1st Call Attempt");

mp.put("Owner",ifnull(leadDetails.get("Owner"),"").get("id"));

mp.put("Call_Type","Outbound");

mp.put("$se_module","Leads");

mp.put("What_Id",leadId);

mp.put("Call_Start_Time",createdtime.toString("yyyy-MM-dd'T'HH:mm:ss"));

mp.put("$which_call","ScheduleCall");

create = zoho.crm.createRecord("Calls",mp);

info mp;

info create;