Get the week of month using date-fns

weekOfMonth.js

import {
    differenceInDays,
    startOfMonth,
    startOfWeek,
    getDate
} from 'date-fns'

const weekOfMonth = function (date) {
    const firstDayOfMonth = startOfMonth(date)
    const firstDayOfWeek = startOfWeek(firstDayOfMonth)
    const offset = differenceInDays(firstDayOfMonth, firstDayOfWeek)
    return Math.ceil((getDate(date) + offset) / 7)
}

export default weekOfMonth