wxml代码：`

<!--wxml-->
<!--日历，记录女性月经周期-->
<view class="calendar"><!--年份和月份-->
<view class="flex calendar-choose"><!--图标-->
<view class="previcon" bindtap="changeMonth">
<image src="../../images/small.png"></image>
</view><!--显示月份-->
<view class="mouth-picker">
<view class="month">{{cur_month}}月</view>
</view><!--显示年份-->
<view class="year-picker">
<view class="year">{{cur_year}}年</view>
</view><!--图标-->
<view class="nexticon" bindtap="changeYear">
<image src="../../images/big.png" ></image>
</view></view><view class="flex week-list">
<view class="week-itm" wx:for="{{weeklist}}">{{item}}</view>
</view><view class="flex days-list">
<view class="day lm" wx:for="{{lastMonthDaysList}}" data-handle="prev">
<text>{{item}}</text>
</view>
<block  wx:for="{{currentMonthDaysList}}">
<view class="day">
<text>{{item}}</text>
</view>
</block>
<view class="day nm" wx:for="{{nextMonthDaysList}}" data-handle="next" >
<text>{{item}}</text>
</view>
</view></view>

wxss代码：

.calendar{width:100%;height:300rpx;}.calendar-choose{height:100rpx;line-height:100rpx;background:#fefefe;padding:0 30rpx;font-size:34rpx;color:#353535;border-bottom: 1rpx solid #e5e5e5;display:flex;justify-content:space-between;
}.calendar .previcon, .calendar .nexticon{width:20%;height:40%;margin-top:12rpx;
}.previcon image, .nexticon image {width:100%;height:100%;
}.calendar .mouth-picker{width:600rpx;text-align: center;}.calendar .year-picker{width:600rpx;text-align: center;}.calendar .week-list
{width:100%;height:70rpx;background:#b9c4c9;display:flex;justify-content:space-around;
}.calendar .week-itm{font-size:30rpx;color:white;width:14.28%;height:100%;padding-left:43rpx;padding-top:15rpx;
}.calendar .days-list{width:100%;display:flex;flex-wrap:wrap;
}.day{width: 14%;height:60rpx;border-right:1rpx solid #e5e5e5;border-bottom:1rpx solid #e5e5e5;color:#333;position: relative;text-align: center;line-height: 60rpx;}.calendar .days-list .lm,.calendar .days-list .nm{color:#b6b6b6;}.calendar .day .ep{color:#333;}

js代码：

Page({data: {cur_month: 0,cur_year: 0,weeklist: ['日', '一', '二', '三', '四', '五', '六']      },                 onLoad: function (options) {var cur_year = new Date().getFullYear();   //获取当前年var cur_month = new Date().getMonth();    //获取当前月this.setData({cur_year: cur_year,cur_month: cur_month + 1});this.calendar(cur_year, cur_month + 1);},//页面相关事件处理函数--监听用户下拉动作onPullDownRefresh: function () {},/**页面上拉触底事件的处理函数**/onReachBottom: function () {},/*用户点击右上角分享*/onShareAppMessage: function () {return {title: '简单日历实现小程序版本',desc: '简单日历实现小程序版本',path: '/pages/index/index'};},calendar: function(year, month) {var days = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31];/*** 本月天数*/if (year % 4 == 0 && year % 100 != 0 || year % 400 == 0) {days[1] = 29;}var day = days[month - 1];/*** 本月第一天星期几*/var myDate = new Date(year, month - 1, 1);var weektime = myDate.getDay();/*** 上个月的天数*/if(month == 1) {var prevyear = year - 1;var prevmonth = 12;var prevday = 31;} else {prevmonth = month - 1;prevday = days[prevmonth - 1];}/*** 下个月的天数*/if(month == 12) {var nextyear = year + 1;var nextmonth = 1;var nextday = 31;} else {nextmonth = month + 1;nextday = days[nextmonth - 1];}/*** 日历上第一个数字*/if(weektime == 0) {var firstnumber = 1;} else {firstnumber = prevday - weektime + 1;}/*** 日历上最后一个数字*/if(firstnumber == 1) {var lastnumber = 7 - (day % 7);} else {if ((prevday - firstnumber + 1 + day) % 7 == 0) {lastnumber = day;} else {var remainder = (prevday - firstnumber + 1 + day) % 7;lastnumber = 7 - remainder;}}var lastMonthDaysList = [];var currentMonthDaysList = [];var nextMonthDaysList = [];if(firstnumber == 1) {lastMonthDaysList = [];} else{for(var i = firstnumber; i <= prevday; i++) {lastMonthDaysList.push(i);}}for(var i = 1; i <= day; i++) {currentMonthDaysList.push(i);}if(lastnumber == day) {nextMonthDaysList = [];} else {for(var i = 1; i <= lastnumber; i++) {nextMonthDaysList.push(i);}}this.setData({lastMonthDaysList: lastMonthDaysList,currentMonthDaysList: currentMonthDaysList,nextMonthDaysList: nextMonthDaysList})},changeMonth: function(e) {var cur_year = this.data.cur_year;if(this.data.cur_month == 1) {var cur_month = 12;cur_year = cur_year - 1;} else {cur_month = this.data.cur_month - 1;}this.setData({cur_year: cur_year,cur_month: cur_month});//console.log('cur_year', cur_year);//console.log('cur_month', cur_month);this.calendar(cur_year, cur_month);},changeYear: function(e) {var cur_year = this.data.cur_year - 1;var cur_month = this.data.cur_month;this.setData({cur_year: cur_year,cur_month: cur_month})this.calendar(cur_year, cur_month);}})

效果图：

（有在网上参考别人的代码，写的不好，欢迎交流。）