weekOfYear
WeekOfYear adiciona a API .week() para retornar o número da semana do ano para um objeto Dayjs.
javascript
var weekOfYear = require('dayjs/plugin/weekOfYear');
// import weekOfYear from 'dayjs/plugin/weekOfYear' // ES 2015
dayjs.extend(weekOfYear);
dayjs('2018-06-27').week(); // 26
dayjs('2018-06-27').week(5); // Define a semana do ano