Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

startOf('month') gives last day in previous month #2007

Open
sts-ryan-holton opened this issue Jul 29, 2022 · 7 comments
Open

startOf('month') gives last day in previous month #2007

sts-ryan-holton opened this issue Jul 29, 2022 · 7 comments

Comments

@sts-ryan-holton
Copy link

Describe the bug

Start of month is incorrect and showing the last day in previous month.

const from = dayjs.tz(dayjs(),'Europe/London').startOf('month')
const end = dayjs.tz(dayjs(),'Europe/London').endOf('month')

The above when console logged outputs:

from: Thu, 30 Jun 2022 23:00:00 GMT
to: Sun, 31 Jul 2022 22:59:59 GMT

Which I think we can all agree is incorrect

Expected behavior

start of time should always return correct times.

Information

  • Day.js Version 1.11.3
  • OS: Latest chrome on Mac OS
  • Browser Chrome
  • Time zone: Europe/London
@Bykiev
Copy link

Bykiev commented Jul 29, 2022 •
edited

Hi, this is a correct result, moment.js has the same result.
Here is a small demo

@sts-ryan-holton
Copy link
Author

@Bykiev cool, except the start of the month isn't June 30th when dayjs() alone returns the current day. So how do I resolve this?

@Bykiev
Copy link

Bykiev commented Jul 29, 2022

GMT is an UTC time, London has an UTC offset +0100

@sts-ryan-holton
Copy link
Author

@Bykiev, Okay, but, in Europe > London right now the start of the month according to my calendar isn't June 30th 🤣, how do I resolve this issue?

@Bykiev
Copy link

Bykiev commented Jul 31, 2022

If you'll use date() function it'll return date of month in a local time. Here is a demo

@BePo65
Copy link
Contributor

BePo65 commented Aug 4, 2022

I created a simple webpage to test the function:

<!DOCTYPE html>
<html lang="en">
  <head>
    <title>dayjs issue #2007</title>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width" />
    <script src="https://unpkg.com/dayjs@1.11.4/dayjs.min.js"></script>
    <script src="https://unpkg.com/dayjs@1.11.4/plugin/utc.js"></script>
    <script src="https://unpkg.com/dayjs@1.11.4/plugin/timezone.js"></script>
  </head>
  <body>
    <style type="text/css">
    body {font: 12px/14px sans-serif}
    .tg  {border-collapse:collapse;border-spacing:0;}
    .tg td{border-color:black;border-style:solid;border-width:1px;font-family:Arial, sans-serif;font-size:14px;
      overflow:hidden;padding:10px 5px;word-break:normal;}
    .tg th{border-color:black;border-style:solid;border-width:1px;font-family:Arial, sans-serif;font-size:14px;
      font-weight:normal;overflow:hidden;padding:10px 5px;word-break:normal;}
    .tg .tg-0pky{border-color:inherit;text-align:left;vertical-align:top}
    </style>
    <main>
      <h1>dayjs issue #2007</h1>
      <table class="tg">
      <tbody>
        <tr>
          <td class="tg-0pky">dayjs().tz('Europe/London').format()</td>
          <td id="dayjs-value" class="tg-0pky"></td>
        </tr>
        <tr>
          <td class="tg-0pky">dayjs.tz(dayjs(),'Europe/London').startOf('month').format()</td>
          <td id="dayjs-start-of-month" class="tg-0pky"></td>
        </tr>
        <tr>
          <td class="tg-0pky">dayjs.tz(dayjs(),'Europe/London').endOf('month').format()</td>
          <td id="dayjs-end-of-month" class="tg-0pky"></td>
        </tr>
      </tbody>
      </table>
    </main>
    <script>
      dayjs.extend(window.dayjs_plugin_utc);
      dayjs.extend(window.dayjs_plugin_timezone);

      const now = dayjs().tz('Europe/London')
      const startOfMonth = dayjs.tz(now,'Europe/London').startOf('month');
      const EndOfMonth = dayjs.tz(now,'Europe/London').endOf('month');
      document.getElementById('dayjs-value').textContent = now.format();
      document.getElementById('dayjs-start-of-month').textContent = startOfMonth.format();
      document.getElementById('dayjs-end-of-month').textContent = EndOfMonth.format();
    </script>
  </body>
</html>

The result is:
TestResult1

So I cannot reproduce this error neither on Chrome 103 nor in Firefox 103 on my windows 10 machine. Could you try this code on your system?

@koluch
Copy link

koluch commented Jun 14, 2023

Hey @Bykiev @BePo65, it feels like I am also facing this bug. I am trying to work in 'Etc/UTC', setting specific date and using .date() function to get a date, but it still returns 31 instead of 1:

image

Here is a code to reproduce: https://codesandbox.io/s/dayjs-playground-forked-sdy6hk?file=/src/index.js. I am using 1.11.8 version

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Assignees
No one assigned
Labels
None yet
Projects
None yet
Milestone
No milestone
Development

No branches or pull requests
4 participants
@koluch @BePo65 @Bykiev @sts-ryan-holton