How to properly infer and set conditions for a groovy loop?

Question

JavaScript

The essence of the question is that there is a certain array of data, it has a value with dates (timestep in milliseconds), you need to build conditions for the cycle that will allow you to find users who received (
something) before a certain point in time.
The output format should be
Name:
Received Date:
So that's the question, how to make such an output format and what condition to use for the loop (to find them).
I hope I phrased everything correctly)

Answer 1

Without knowing the exact format of the input data (an array of objects or an array of arrays or something else), it is impossible to give an exact answer. Well, I will give a solution for one of the options:

const startDate = new Date("2019-01-01") // ключевая дата
const inTmStamp = startDate.getTime()
const data = [
['Anton', 1352300800000],
['Igor', 1546300800000],
['Vasiliy', 1559300809800],
['Stephan', 1546300800000],
['Jose', 1446300800000],
]
function leadZero(str){ // добавляет ноль спереди, если цифра одна
    return String(str).length<2 ? '0'+str : str
}
function formatTime(dt){
    // нумерация месяцев с 0, поэтому +1
    return dt.getFullYear() + '-' + leadZero(dt.getMonth()+1) + '-' + leadZero(dt.getDay())
}
const res = data.filter(arr => arr[1] < inTmStamp).map(arr => {
    const dt = new Date(arr[1])
    return {
        'Дата создания':  formatTime(dt),
        'Сотрудник': arr[0]
    }
})
console.log(JSON.stringify(res))