mongoose pre save hook

[vardges-musheghyan]

Hi I am implementing a booking application and I need to check the start date of the appointment and if it is today then I need to split my appointments into two differents appointments one of which is e.g
today is 2020-01-26;
start_date is 2020-01-26
end_date is 2020-01-29

then I will need to have one two appointments one of which is

appointment 1 - start_date = 2020-01-26, end_date = 2020-01-26;
appointment2 - start_date = 2020-01-27, end_date = 2020-01-29;

I am trying to do it in pre save hook,
can someone please explain me how this could be implemented in mongoose world

const ReservationSchema = new Schema({
  start_date: {
    type: Date,
    required: true,
    index: true,
  },
  end_date: {
    type: Date,
    index: true,
  },
  user_id: {
    type: Schema.Types.ObjectId,
    ref: 'User',
    required: true,
  },
  team_id: {
    type: Schema.Types.ObjectId,
    ref: 'Team',
    required: true,
    index: true,
  },
  table_id: {
    type: Schema.Types.ObjectId,
    ref: 'Table',
    required: true,
    index: true,
  },
  chair_id: {
    type: Schema.Types.ObjectId,
    ref: 'Chair',
    required: true,
  },
  status: {
    type: String,
    enum: ['pending', 'approved', 'rejected'],
    default: 'pending',
  },
}, { timestamps: true });

ReservationSchema.pre('save', async function (next){

})