javascript 你如何在javascript中获得今天开始的unix时间戳？
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How do you get the unix timestamp for the start of today in javascript?
提问by Anthony Hyman
I realize that the current timestamp can be generated with the following...
我意识到可以使用以下内容生成当前时间戳...
var timestamp = Math.round((new Date()).getTime() / 1000);
What I'd like is the timestamp at the beginning of the current day. For example the current timestamp is roughly 1314297250, what I'd like to be able to generate is 1314230400which is the beginning of today August 25th 2011.
我想要的是当天开始时的时间戳。例如，当前时间戳大致是1314297250，我希望能够生成的是1314230400which is the begin of today August 25th 2011。
Thanks for your help.
谢谢你的帮助。
回答by Tim Down
var now = new Date();
var startOfDay = new Date(now.getFullYear(), now.getMonth(), now.getDate());
var timestamp = startOfDay / 1000;
回答by Luis Fontes
Well, the cleanest and fastest way to do this is with:
好吧，最干净和最快的方法是：
long timestamp = 1314297250;
long beginOfDay = timestamp - (timestamp % 86400);
where 86400 is the number of seconds in one day
其中 86400 是一天的秒数
回答by pimvdb
var now = new Date; // now
now.setHours(0); // set hours to 0
now.setMinutes(0); // set minutes to 0
now.setSeconds(0); // set seconds to 0
var startOfDay = Math.floor(now / 1000); // divide by 1000, truncate milliseconds
回答by Alex Turpin
var d = new Date();
d.setHours(0);
d.setMinutes(0);
d.setSeconds(0);
d.setMilliseconds(0);
var t = d / 1000;
回答by Joseph Marikle
Another alternative for getting the beginning of the day is the following:
开始一天的另一种选择如下：
var now = new Date();
var beginningOfDay = new Date(now.getTime() -
now.getHours() * 60 * 60 * 1000 -
now.getMinutes() * 60 * 1000 -
now.getSeconds() * 1000 -
now.getMilliseconds());
回答by Henry Brewer
Luis Fontes' solution returns UTC timeso it can be 1 hour (daylight saving time) different from setHours solution.
Luis Fontes 的解决方案返回UTC 时间，因此它可能与 setHours 解决方案相差 1 小时（夏令时）。
var d = new Date();
var t = d - (d % 86400000);
Simplified version of examples above (local time).
上述示例的简化版本（当地时间）。
var d = new Date();
d.setHours(0,0,0,0);
var t = d / 1000;
Here you can find some performance tests: http://jsperf.com/calc-start-of-day
在这里你可以找到一些性能测试：http: //jsperf.com/calc-start-of-day
回答by digitalWestie
Alternatively you could subtract the modulo of a days length in miliseconds e.g.
或者，您可以减去以毫秒为单位的天长度的模数，例如
var day = 24*60*60*1000;
var start_of_today = Date.now() - Date.now() % day;
回答by Alexander
For any date it's easy to get Timestamps of start/end of the date using ISO String of the date ('yyyy-mm-dd'):
对于任何日期，使用日期的 ISO 字符串 ('yyyy-mm-dd') 可以轻松获取日期开始/结束的时间戳：
var dateString = '2017-07-13';
var startDateTS = new Date(`${dateString}T00:00:00.000Z`).valueOf();
var endDateTS = new Date(`${dateString}T23:59:59.999Z`).valueOf();
To get ISO String of today you would use (new Date()).toISOString().substring(0, 10)So to get TS for today:
要获得今天的 ISO 字符串，您将使用(new Date()).toISOString().substring(0, 10)So 来获得今天的 TS：
var dateString = (new Date()).toISOString().substring(0, 10);
var startDateTS = new Date(`${dateString}T00:00:00.000Z`).valueOf();
var endDateTS = new Date(`${dateString}T23:59:59.999Z`).valueOf();
回答by Venkat Kotra
var now = new Date();
var startOfDay = new Date(now.getFullYear(), now.getMonth(), now.getDate());
var timestamp = startOfDay.getTime() / 1000;
回答by Vu Anh
var yoursystemday = new Date(new Date().getTime()-(120000*60+new Date().getTimezoneOffset()*60000));
yoursystemday = new Date();
var current_time_stamp = Math.round(yoursystemday.getTime()/1000);
