具有相同日期格式的javascript日期

Question

[我在javascript date中面临问题。我想使用相同的日期格式previous date和start date

Excepted Output上一个日期

[12AM之后显示00:00:00到12:00:00

[下午12点之后显示00:00:00至12:00:00

格式

previous date 2020-05-10 16:31:28

开始日期

2020-05-10 02:00:00              //sample data
2020-05-10 05:00:00

我的代码：

var currentdate = new Date();
var prevdate = new Date(); //previous date

prevdate.setTime(currentdate.getTime() - (30 * 60 * 1000));

var newprevious = GetFormattedDate(prevdate);
console.log(newprevious);

//Date format yyyy-mm-dd h:MM:ss
function GetFormattedDate(date) {
  var month = ("0" + (date.getMonth() + 1)).slice(-2);
  var day = ("0" + (date.getDate())).slice(-2);
  var year = date.getFullYear();
  var hour = ("0" + (date.getHours())).slice(-2);
  var min = ("0" + (date.getMinutes())).slice(-2);
  var seg = ("0" + (date.getSeconds())).slice(-2);
  return year + "-" + month + "-" + day + " " + hour + ":" + min + ":" + seg;
}

注意：我不能更改开始日期，它是

var currentdate = new Date();
var prevdate = new Date(); //previous date

prevdate.setTime(currentdate.getTime() - (30 * 60 * 1000));

var newprevious = GetFormattedDate(prevdate);
console.log(newprevious);

//Date format yyyy-mm-dd h:MM:ss
function GetFormattedDate(date) {
  var month = ("0" + (date.getMonth() + 1)).slice(-2);
  var day = ("0" + (date.getDate())).slice(-2);
  var year = date.getFullYear();
  var hour = ("0" + (date.getHours())).slice(-2);
  var min = ("0" + (date.getMinutes())).slice(-2);
  var seg = ("0" + (date.getSeconds())).slice(-2);
  return year + "-" + month + "-" + day + " " + hour + ":" + min + ":" + seg;
}

格式

我应该改变什么？有人帮我吗？

Answer 1

如果问题仅在于小时不是am / pm格式，则可以使用模运算符（我还在字符串末尾添加了am / pm）以这种方式修改函数：

fixed

Answer 2

这确实是日期格式问题，因此很可能是

var currentdate = new Date();
var prevdate = new Date(); //previous date

prevdate.setTime(currentdate.getTime() - (30 * 60 * 1000));

var newprevious = GetFormattedDate(prevdate);
console.log(newprevious);

//Date format yyyy-mm-dd h:MM:ss
function GetFormattedDate(date) {
  var month = ("0" + (date.getMonth() + 1)).slice(-2);
  var day = ("0" + (date.getDate())).slice(-2);
  var year = date.getFullYear();
  
  // EDIT:
  var hour = date.getHours()%12; // using the modulo operator, you convert the hours to a range between 0 and 12

  if (hour == 0) {
      hour = 12;
  }
  
  var timeOfDay = "am";      

  if (date.getHours() >= 12) {
      timeOfDay = "pm";
  }

  hour = ("0" + hour).slice(-2);
  
 // END EDIT

  var min = ("0" + (date.getMinutes())).slice(-2);
  var seg = ("0" + (date.getSeconds())).slice(-2);
  return year + "-" + month + "-" + day + " " + hour + ":" + min + ":" + seg + " " + timeOfDay;
}

的副本。

正如Drago96回答的那样，您可以使用余数运算符％来修改小时值，并在适当时添加上午或下午

使用get方法和处理每个部分的替代方法是使用How to format a JavaScript date和Intl.DateTimeFormat object的格式设置选项，例如

formatToParts