JavaScript Date to C# DateTime Changes TimeZone

i have my Angular code like so:

export interface angularModel {
  name: string;
  createdOnDate: Date;
  decision: {
    id: number;
    createdOnDate: Date;
  }
}
const now = new Date();//outputs Thu Sep 15 2022 09:19:05 GMT-0700 (Mountain Standard Time)
const document = new angularModel();
document = {
  name: 'Bob',
  createdOnDate: now
  decision: {
    id: 1,
    createdOnDate: now
  }
}

but on the API side, this is received as:

CustomModel document = {
  Name: "Bob",
  CreatedOnDate: {9/15/2022 9:19:05 AM},//which is correct
  AutoGeneratedModel Decision: {
    Id: 1,
    CreatedOnDate: {9/15/2022 4:19:05 PM}//which is wrong
  }
}

the CustomModel is setup like this:

using System;
using System.Collections.Generic;

namespace Project.Models
{
  public class CustomModel
  {
    public string Name { get; set; }
    public DateTime CreatedOnDate { get; set; }
    public AutoGeneratedModel Decision { get; set; }
  }
}

and the AutoGeneratedModel is setup like this:

namespace Project.Contexts
{
  using System;
  using System.Collections.Generic;
  using System.Runtime.Serialization;
    
  [DataContract(IsReference=true)]
  public partial class AutoGeneratedModel
  {
    [DataMember]
    public int Id { get; set; }
    [DataMember]
    public System.DateTime CreatedOnDate { get; set; }
  }
}

and i have no idea why the time zone changes in the one instance.