Question

我想计算一个给定的日期是从今天还是昨天开始。目前我只能检查它是24小时还是48小时。我该如何查看日期？

var date_given = new Date(Date.parse(item.date));

var today = new Date();
var diff = ( Date.parse(today) - Date.parse(date_given) ) /(1000*24*60*60);

if (diff < 1) {
    return "today";
} else if (diff < 2) {
    return "yesterday";
}

Answer 1

您可以使用这些功能添加任意天数（负数）并确定日期的日期部分是否相等：

var msInDay = 86400000;

function addDays(date, add) {
    return new Date(date.valueOf() + (msInDay * add));
}

function isSameDay(a, b) {
    return a.getFullYear() == b.getFullYear() &&
        a.getMonth() == b.getMonth() &&
        a.getDate() == b.getDate();
}

这将允许你昨天得到：

var today = new Date();
var yesterday = addDays(today, -1);

现在比较：

var otherDate = addDays(today, -1);
var isYesterday = isSameDay(otherDate, yesterday);
var isToday = isSameDay(otherDate, today);

Answer 2

你可以这样做旧学校：

var dateTime = function(args) {
  args = args || [0,0,0,0]
  var d = new Date(Date.now())
  d.setUTCHours(args[0])
  d.setUTCMinutes(args[1])
  d.setUTCSeconds(args[2])
  d.setUTCMilliseconds(args[3])
  return d;
}

var isItTodayOrYesterday = function(given) {
  var start = dateTime(),
      end   = dateTime([23,59,59,999])
  return given < start ? 'yesterday' : given < end ? 'today' : "its the futur man"
}

var futur = new Date('December 17, 2018 03:24:00'),
    today = new Date(),
    past  = new Date('December 17, 1995 03:24:00');

console.log(isItTodayOrYesterday(past)) // yesterday
console.log(isItTodayOrYesterday(today)) // today
console.log(isItTodayOrYesterday(futur)) // its the futur man

请参阅this fiddle

修改

根据您的评论，这是一个负责yesterday案例的版本：

var dateTime = function(args) {
  var time = (args && args.time) ? args.time : [0,0,0,0],
      date = new Date((args && args.date) || Date.now())

  date.setUTCHours(time[0])
  date.setUTCMinutes(time[1])
  date.setUTCSeconds(time[2])
  date.setUTCMilliseconds(time[3])
  return date;
}

console.clear()

var isItTodayOrYesterday = function(given) {
  var start     = dateTime(),
      yesterday = dateTime({date: new Date(new Date().valueOf() - 3600 * 24 * 1000)}),
      end       = dateTime({time: [23,59,59,999]})

  return given < yesterday ? "we're stuck in the past" 
    : given < start ? 'yesterday' 
      : given < end ? 'today' 
        : "its the futur man"
}

var futur       = new Date('December 17, 2018 03:24:00'),
    today       = new Date(),
    past        = new Date('December 17, 1995 03:24:00'),
    yesterday   = dateTime({
      date: new Date(new Date().valueOf() - 3600 * 24 * 1000),
      time: [12,21,30,0]
    });

console.log(isItTodayOrYesterday(past)) // "we're stuck in the past"
console.log(isItTodayOrYesterday(yesterday)) // yesterday
console.log(isItTodayOrYesterday(today)) // today
console.log(isItTodayOrYesterday(futur)) // its the futur man

请参阅the updated fiddle

Answer 3

如果您只想查看给定日期是今天还是昨天，那么只需尝试此功能。您不需要编写很长的代码：

function checkTodayYesterday(givenDate) {
    var today = new Date();
    var yesterday = new Date();
    yesterday.setDate(yesterday.getDate() - 1);
    if(today.toDateString() === givenDate.toDateString()) {
        console.log('givenDate is today');
    } else if(yesterday.toDateString() === givenDate.toDateString()) {
        console.log('givenDate is yesterday');
    } else  {
        console.log('givenDate is other than today or yesterday');
    }
}

快乐的编码！：）

如果给定日期是今天的日期或昨天的日期，如何计算？

3 个答案: