<div class="box"> <header class='control'> <input id="conYear" class="con-in" type="number" min="1900" max="2100" step="1"/> <input id="conMonth" class="con-in" type="number" min="1" max="12" step="1"/> </header> <div class="DateBox"> <header class='week'> <div class="week-in">周日</div> <div class="week-in">周一</div> <div class="week-in">周二</div> <div class="week-in">周三</div> <div class="week-in">周四</div> <div class="week-in">周五</div> <div class="week-in">周六</div> </header> <section class="dayBox" id='dayBox'> <div class="day" id="day1">1</div> <div class="day">2</div> <div class="day">3</div> <div class="day">4</div> <div class="day">5</div> <div class="day">6</div> <div class="day">7</div> <div class="day">8</div> <div class="day">9</div> <div class="day">10</div> <div class="day">11</div> <div class="day">12</div> <div class="day">13</div> <div class="day">14</div> <div class="day">15</div> <div class="day">16</div> <div class="day">17</div> <div class="day">18</div> <div class="day">19</div> <div class="day">20</div> <div class="day">21</div> <div class="day">22</div> <div class="day">23</div> <div class="day">24</div> <div class="day">25</div> <div class="day">26</div> <div class="day">27</div> <div class="day">28</div> <div class="day">29</div> <div class="day" id="day30">30</div> <div class="day" id="day31">31</div> </section> </div> </div>

body{ margin: 0;}input{ border: none; padding: 0;}.box{ width: 354px; margin: 30px auto 0; }.DateBox{ height: 300px; border: 2px solid black;} .week{ overflow: hidden; border-bottom: 1px solid black; line-height: 49px;}.week-in{ height: 49px; float: left; width: 50px; text-align: center;}.dayBox{ overflow: hidden;}.day{ float: left; height: 50px; width: 50px; font:20px/50px '微軟雅黑'; text-align: center;}.control{ overflow: hidden;}.con-in{ height: 50px; float: left; width: 100px; text-align: center; font: 20px/50px "微軟雅黑";}

//準備:獲取當前樣式function getCSS(obj,style){ if(window.getComputedStyle){ return getComputedStyle(obj)[style]; } return obj.currentStyle[style];}//實現一：獲取當月的天數，及當月第一天、第30日、第31日是星期幾function get_data(year,month){ var result = {}; var d = new Date(); //如果是2月 if(month == 2){ //如果是閏年 if((year % 4 === 0 && year % 100 !== 0) || year % 400 === 0){ result.days = 29; //如果是平年 }else{ result.days = 28; } //如果是第4、6、9、11月 }else if(month == 4 || month == 6 ||month == 9 ||month == 11){ result.days = 30; }else{ result.days = 31; //當月第31天是星期幾 result.day31week = d.getDay(d.setFullYear(year,month-1,31)); } //當月第一天是星期幾 result.day1week = d.getDay(d.setFullYear(year,month-1,1)); if(month != 2){ //當月第30天是星期幾 result.day30week = d.getDay(d.setFullYear(year,month-1,30));  } return result;}//實現二：根據當月第一天的星期x，設置第一天的margin-left=寬度*x，使其對應到正確的星期位置上function move_day1(year,month){ var week1 = get_data(year,month).day1week; day1.style.marginLeft = week1%7*parseInt(getCSS(day1,'width'))+ 'px';}//實現三：根據當月的天數，來隱藏多余的天數。當然首先要先顯示在其他月份被隱藏的天數function hide_days(year,month){ //恢復其他月份可能隱藏的天數 for(var i = 28; i<31; i++){ dayBox.children[i].style.display = 'block'; }  //隱藏當月多余的天數 var days = get_data(year,month).days; for(var i = days;i<31;i++){ dayBox.children[i].style.display = 'none'; }};//實現四：如果當月30日或31日是星期日，則會新占一行，通過設置margin-top把新占一行的天移動到第一行function move_day30(year,month){ //如果當月30日是星期日 if(get_data(year,month).day30week === 0){ day30.style.marginTop = parseInt(getCSS(day30,'height')) *(-5) + 'px'; day31.style.marginTop = parseInt(getCSS(day31,'height')) *(-5) + 'px'; day31.style.marginLeft= getCSS(day31,'width'); return; }else{ day30.style.marginTop = day31.style.marginTop = day31.style.marginLeft ='0'; } //如果當月31日是星期日 if(get_data(year,month).day31week === 0){ day31.style.marginTop = parseInt(getCSS(day31,'height')) *(-5) + 'px'; }else{ day31.style.marginTop = '0'; }}//實現五：當載入頁面時，獲取當前年和月，顯示當月日歷；當改變年或月時，獲取改變后的年和月，更新當月日歷var year= conYear.value=new Date().getFullYear();var month= conMonth.value = new Date().getMonth() + 1;move_day1(year,month);hide_days(year,month);move_day30(year,month);conYear.onchange = conMonth.onchange = function(){ var year = conYear.value; var month = conMonth.value; if(year<1900 || year >2100 ){ year = conYear.value=new Date().getFullYear(); } if(month<1 || month > 12){ month = conMonth.value=new Date().getMonth() + 1; } move_day1(year,month); hide_days(year,month); move_day30(year,month);}