Nex Day без Date

//6 Exercise: Basic Syntax, Conditional Statements and Loops/More Exercise/03. Next Day.js
nextDay1 = (year, month, day) => {
  'use strict'

  let yearNext = year
  let monthNext = month
  let dayNext = day

  if (year <= 99 && year >= 0)
    yearNext += 1900

  const isLeapYear = (year) => ((year % 4 === 0 && year % 100 !== 0) || year % 400 === 0) ? true : false

  let months = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]

  if (isLeapYear(year))
    months[1] = 29

  if (month === 12 && day === 31) {
    yearNext = ++yearNext
    monthNext = 1
    dayNext = 1
  } else if (day === months[month - 1]) {
    monthNext = ++month
    dayNext = 1
  } else {
    dayNext = ++day
  }

  console.log(`${yearNext}-${monthNext}-${dayNext}`)
}