Grouping Array by another array 'createdAt' values

i have 2 arrays from my Api
this

passArray:[
{pass_id: 645, heure_debut: '13:48:00', heure_fin: '14:48:00', createdAt:"2023-08-03T13:48:00.000Z"}
{pass_id: 646, heure_debut: '14:40:00', heure_fin: '15:40:00', createdAt:"2023-08-03T14:40:00.000Z"}
{pass_id: 647, heure_debut: '20:30:00', heure_fin: '21:30:00', createdAt:"2023-08-04T20:30:00.000Z"}
{pass_id: 648, heure_debut: '13:00:00', heure_fin: '14:00:00', createdAt:"2023-08-04T13:00:00.000Z"}
{pass_id: 649, heure_debut: '16:25:00', heure_fin: '17:25:00', createdAt:"2023-08-05T16:25:00.000Z"}
{pass_id: 650, heure_debut: '18:30:00', heure_fin: '19:30:00', createdAt:"2023-08-05T18:30:00.000Z"}

]

array2:[
{horaire_id: 5, operation: 'opened', user_id: 1, createdAt: '2023-08-03T12:15:46.000Z'}
{horaire_id: 7, operation: 'closed', user_id: 1, createdAt: '2023-08-04T12:21:29.000Z'}
{horaire_id: 8, operation: 'opened', user_id: 1, createdAt: '2023-08-04T12:29:04.000Z'}
{horaire_id: 9, operation: 'closed', user_id: 1, createdAt: '2023-08-05T07:57:16.000Z'}
{horaire_id: 10, operation: 'opened',user_id: 1, createdAt: '2023-08-05T08:04:48.000Z'}
{horaire_id: 11, operation: 'closed',user_id: 1, createdAt: '2023-08-06T03:06:56.000Z'}
]

i want to groupe passArray by 'createdAt' filtered by Array2 'createdAt' interval 'opened and closed'
i dont know if i must to use reduce or filter ?

I wish to have as a result something like that

2023-08-03T12:15:46.000Z :
{pass_id: 645, heure_debut: '13:48:00', heure_fin: '14:48:00', createdAt:"2023-08-03T13:48:00.000Z"}
{pass_id: 646, heure_debut: '14:40:00', heure_fin: '15:40:00', createdAt:"2023-08-03T14:40:00.000Z"},

2023-08-04T12:29:04.000Z:
{pass_id: 647, heure_debut: '20:30:00', heure_fin: '21:30:00', createdAt:"2023-08-04T20:30:00.000Z"}
{pass_id: 648, heure_debut: '13:00:00', heure_fin: '14:00:00', createdAt:"2023-08-04T13:00:00.000Z"}

2023-08-05T07:57:16.000Z:
{pass_id: 649, heure_debut: '16:25:00', heure_fin: '17:25:00', createdAt:"2023-08-05T16:25:00.000Z"}
{pass_id: 650, heure_debut: '18:30:00', heure_fin: '19:30:00', createdAt:"2023-08-05T18:30:00.000Z"}

the final goal is to obtain at the end the number of pass in passArray in an interval of opened and closed of array2.
thinks

reduce ? or filter ? or map ? i dont know

Ideally, we'd be able to see what you have so far so we can offer advice or a potential solution from that. Since that is not present, I will give you an idea of what I would do to tackle this.

function groupPasses(passArray, array2) {
    // Create an array of the intervals from array2
    let intervals = [];
    for(let i = 0; i < array2.length; i += 2){
        if(array2[i] && array2[i+1]){
            intervals.push({
                start: new Date(array2[i].createdAt),
                end: new Date(array2[i+1].createdAt)
            });
        }
    }

    // Use reduce to create an object where the keys are the createdAt dates
    // and the values are arrays of elements from passArray that fall within the interval
    return passArray.reduce((acc, pass) => {
        let passDate = new Date(pass.createdAt);

        // Use filter to find the interval that the pass falls in
        let interval = intervals.filter((interval) => 
            passDate >= interval.start && passDate <= interval.end
        )[0];

        if(interval){
            let key = interval.start.toISOString();
            if(!acc[key]){
                acc[key] = [];
            }

            acc[key].push(pass);
        }

        return acc;
    }, {});
}

This function first creates an array of intervals from array2. Then it iterates over passArray using reduce. For each element in passArray, it uses filter to find the interval from array2 that the element's createdAt date falls within. It then adds the element to the appropriate array in the object it's creating.

Remember to ensure that array2 is sorted in ascending order by the createdAt property before using this function. This function assumes that every 'opened' operation in array2 is followed by a 'closed' operation.

The final object created by this function will have keys that are the start dates of the intervals in array2, and the values are arrays of elements from passArray that fall within those intervals. You can get the number of passes in each interval by getting the length of these arrays.