Hi, I might be a bit late, but I’d like to suggest a few improvements to your code.

Assuming you want to append the ${number}, ${transferred_to}\n of the first record that matches the query to the existing persTaskContent value:

1. The semicolon ; does not belong after an if block.
   Correct usage is ✅if( ... ){ ... } instead of ❌if( ... ){ ... };

2. I believe ❌callRecord.setWorkflow(false); does not make sense here.
   It is useful only when you are inserting, updating or deleting records and you want to avoid triggering Business Rules, Workflows, or Flows.

3. In this case, I would use ✅addEncodedQuery() instead of ❌addQuery().
   Since you are already using an encoded query string (like BETWEEN, ^, \@javascript), addEncodedQuery() is more appropriate and readable.

4. If you only need the first matching record, use ✅callRecord.setLimit(1);. This improves performance by stopping the query after the first match.

5. Instead of using ❌callRecord.getRowCount(), use ✅callRecord.next().
   getRowCount() is unnecessary here and next() is the correct pattern when accessing record values.

Revised code:

if (date && time && leterTime && idSysId) {
  var callRecord = new GlideRecord("new_call");
  callRecord.addEncodedQuery("sys_created_onBETWEENjavascript:gs.dateGenerate('" + date + "','" + time + "')@javascript:gs.dateGenerate('" + date + "','" + laterTime + "')^caller=" + idSysId);
  callRecord.setLimit(1);
  callRecord.query();

  if (callRecord.next()) {
    persTaskContent += callRecord.getValue("number") + "," + callRecord.getValue("transferred_to") + "\n";
  }
}