Mongo / Mongoose - Как редактировать вложенную структуру

У меня есть коллекция, которая выглядит вот так. Каждый Объект в «днях» - это свой «дневной» документ. Более того, он не разбивается. Вот структура:

 days: [
        {
            day: 'Sunday', 
            slots: [
                {time: '12:00am', event: null}, {time: '1:00am', event: null}, {time: '2:00am', event: null}, {time: '3:00am', event: null}, 
                {time: '4:00am', event: null}, {time: '5:00am', event: null}, {time: '6:00am', event: null}, {time: '7:00am', event: null}, 
                {time: '8:00am', event: null}, {time: '9:00am', event: null}, {time: '10:00am', event: null}, {time: '11:00am', event: null}, 
                {time: '12:00pm', event: null}, {time: '1:00pm', event: null}, {time: '2:00pm', event: null}, {time: '3:00pm', event: null}, 
                {time: '4:00pm', event: null}, {time: '5:00pm', event: null}, {time: '6:00pm', event: null}, {time: '7:00pm', event: null}, 
                {time: '8:00pm', event: null}, {time: '9:00pm', event: null}, {time: '10:00pm', event: null}, {time: '11:00pm', event: null}, 
            ]
        },
        {
            day: 'Monday', 
            slots: [
                {time: '12:00am', event: null}, {time: '1:00am', event: null}, {time: '2:00am', event: null}, {time: '3:00am', event: null}, 
                {time: '4:00am', event: null}, {time: '5:00am', event: null}, {time: '6:00am', event: null}, {time: '7:00am', event: null}, 
                {time: '8:00am', event: null}, {time: '9:00am', event: null}, {time: '10:00am', event: null}, {time: '11:00am', event: null}, 
                {time: '12:00pm', event: null}, {time: '1:00pm', event: null}, {time: '2:00pm', event: null}, {time: '3:00pm', event: null}, 
                {time: '4:00pm', event: null}, {time: '5:00pm', event: null}, {time: '6:00pm', event: null}, {time: '7:00pm', event: null}, 
                {time: '8:00pm', event: null}, {time: '9:00pm', event: null}, {time: '10:00pm', event: null}, {time: '11:00pm', event: null}, 
            ]
        },
        {
            day: 'Tuesday', 
            slots: [
                {time: '12:00am', event: null}, {time: '1:00am', event: null}, {time: '2:00am', event: null}, {time: '3:00am', event: null}, 
                {time: '4:00am', event: null}, {time: '5:00am', event: null}, {time: '6:00am', event: null}, {time: '7:00am', event: null}, 
                {time: '8:00am', event: null}, {time: '9:00am', event: null}, {time: '10:00am', event: null}, {time: '11:00am', event: null}, 
                {time: '12:00pm', event: null}, {time: '1:00pm', event: null}, {time: '2:00pm', event: null}, {time: '3:00pm', event: null}, 
                {time: '4:00pm', event: null}, {time: '5:00pm', event: null}, {time: '6:00pm', event: null}, {time: '7:00pm', event: null}, 
                {time: '8:00pm', event: null}, {time: '9:00pm', event: null}, {time: '10:00pm', event: null}, {time: '11:00pm', event: null}, 
            ]
        },
        {
            day: 'Wednesday', 
            slots: [
                {time: '12:00am', event: null}, {time: '1:00am', event: null}, {time: '2:00am', event: null}, {time: '3:00am', event: null}, 
                {time: '4:00am', event: null}, {time: '5:00am', event: null}, {time: '6:00am', event: null}, {time: '7:00am', event: null}, 
                {time: '8:00am', event: null}, {time: '9:00am', event: null}, {time: '10:00am', event: null}, {time: '11:00am', event: null}, 
                {time: '12:00pm', event: null}, {time: '1:00pm', event: null}, {time: '2:00pm', event: null}, {time: '3:00pm', event: null}, 
                {time: '4:00pm', event: null}, {time: '5:00pm', event: null}, {time: '6:00pm', event: null}, {time: '7:00pm', event: null}, 
                {time: '8:00pm', event: null}, {time: '9:00pm', event: null}, {time: '10:00pm', event: null}, {time: '11:00pm', event: null}, 
            ]
        },
        {
            day: 'Thursday', 
            slots: [
                {time: '12:00am', event: null}, {time: '1:00am', event: null}, {time: '2:00am', event: null}, {time: '3:00am', event: null}, 
                {time: '4:00am', event: null}, {time: '5:00am', event: null}, {time: '6:00am', event: null}, {time: '7:00am', event: null}, 
                {time: '8:00am', event: null}, {time: '9:00am', event: null}, {time: '10:00am', event: null}, {time: '11:00am', event: null}, 
                {time: '12:00pm', event: null}, {time: '1:00pm', event: null}, {time: '2:00pm', event: null}, {time: '3:00pm', event: null}, 
                {time: '4:00pm', event: null}, {time: '5:00pm', event: null}, {time: '6:00pm', event: null}, {time: '7:00pm', event: null}, 
                {time: '8:00pm', event: null}, {time: '9:00pm', event: null}, {time: '10:00pm', event: null}, {time: '11:00pm', event: null}, 
            ]
        },
        {
            day: 'Friday', 
            slots: [
                {time: '12:00am', event: null}, {time: '1:00am', event: null}, {time: '2:00am', event: null}, {time: '3:00am', event: null}, 
                {time: '4:00am', event: null}, {time: '5:00am', event: null}, {time: '6:00am', event: null}, {time: '7:00am', event: null}, 
                {time: '8:00am', event: null}, {time: '9:00am', event: null}, {time: '10:00am', event: null}, {time: '11:00am', event: null}, 
                {time: '12:00pm', event: null}, {time: '1:00pm', event: null}, {time: '2:00pm', event: null}, {time: '3:00pm', event: null}, 
                {time: '4:00pm', event: null}, {time: '5:00pm', event: null}, {time: '6:00pm', event: null}, {time: '7:00pm', event: null}, 
                {time: '8:00pm', event: null}, {time: '9:00pm', event: null}, {time: '10:00pm', event: null}, {time: '11:00pm', event: null}, 
            ]
        },
        {
            day: 'Saturday', 
            slots: [
                {time: '12:00am', event: null}, {time: '1:00am', event: null}, {time: '2:00am', event: null}, {time: '3:00am', event: null}, 
                {time: '4:00am', event: null}, {time: '5:00am', event: null}, {time: '6:00am', event: null}, {time: '7:00am', event: null}, 
                {time: '8:00am', event: null}, {time: '9:00am', event: null}, {time: '10:00am', event: null}, {time: '11:00am', event: null}, 
                {time: '12:00pm', event: null}, {time: '1:00pm', event: null}, {time: '2:00pm', event: null}, {time: '3:00pm', event: null}, 
                {time: '4:00pm', event: null}, {time: '5:00pm', event: null}, {time: '6:00pm', event: null}, {time: '7:00pm', event: null}, 
                {time: '8:00pm', event: null}, {time: '9:00pm', event: null}, {time: '10:00pm', event: null}, {time: '11:00pm', event: null}, 
            ]
        }
    ]

Я хотел бы отредактировать поле события, которое вложено в этот json. Как я мог это сделать? У меня есть дневная модель. Но дальше этого не происходит. Я думал об использовании findOneAndUpdate, но я не могу понять, как развернуть, поэтому я нахожусь в подходящем временном интервале. Конечная точка имеет доступ к дню, времени и значению для установки события.