date-fns时间库的基本使用

在react中使用date-fns：

import sub_days from 'date-fns/sub_days';

import start_of_week from 'date-fns/start_of_week';

import end_of_week from 'date-fns/end_of_week';

import start_of_month from 'date-fns/start_of_month';

import end_of_month from 'date-fns/end_of_month';

 

const theMoment = new Date();

const today = +theMoment;

const yerterday = +sub_days(theMoment, 1);

const startOfWeek = +start_of_week(theMoment, { weekStartsOn: 1 });

const endOfWeek = +end_of_week(theMoment, { weekStartsOn: 1 });

const startOfMonth = +start_of_month(theMoment);

const endOfMonth = +end_of_month(theMoment);

 

不使用时间库：

let date = new Date()

let lastDay = new Date(date.getTime() - 24 * 60 * 60 * 1000) //昨天

let currentMonth = date.getMonth()

let nextMonth = ++currentMonth

let nextMonthFirstDay = new Date(date.getFullYear(), nextMonth, 1)

let oneDay = 1000 * 60 * 60 * 24

//返回date是一周中的某一天

let week = date.getDay()

//返回date是一个月中的某一天

let month = date.getDate()

//减去的天数

let minusDay = week != 0 ? week - 1 : 6

//获得当前周的第一天

let currentWeekFirstDay = new Date(date.getTime() - oneDay * minusDay)

//获得当前周的最后一天

let currentWeekLastDay = new Date(currentWeekFirstDay.getTime() + oneDay * 6)