日期相加的函数addDate

 1<script language="JavaScript">   
 2<!-- 
 3
 4function addDate(type,NumDay,dtDate){   
 5var date = new Date(dtDate)   
 6type = parseInt(type) //类型   
 7lIntval = parseInt(NumDay)//间隔   
 8switch(type){   
 9case 6 ://年   
10date.setYear(date.getYear() + lIntval)   
11break;   
12case 7 ://季度   
13date.setMonth(date.getMonth() + (lIntval * 3) )   
14break;   
15case 5 ://月   
16date.setMonth(date.getMonth() + lIntval)   
17break;   
18case 4 ://天   
19date.setDate(date.getDate() + lIntval)   
20break   
21case 3 ://时   
22date.setHours(date.getHours() + lIntval)   
23break   
24case 2 ://分   
25date.setMinutes(date.getMinutes() + lIntval)   
26break   
27case 1 ://秒   
28date.setSeconds(date.getSeconds() + lIntval)   
29break;   
30default:   
31  
32}   
33return date.getYear() +'-' + (date.getMonth()+1) + '-' +date.getDate()+ ' '+ date.getHours()+':'+date.getMinutes()+':'+date.getSeconds()   
34}   
35document.write(addDate("5",5,"2005/5/21 00:00:00"))   
36//-->   
37</script>