Missing timezone in metadata date can lead to wrong date in url

[zwippie]

Starting with a fresh new Jekyll site with no modifications, I noticed that the first auto-generated post got the wrong page date when served. It looks like a missing timezone in the posts metadata can lead to the generated url being one day off when the time is close enough to midnight.

Metadata of file /_posts/2013-05-09/welcome-to-jekyll.markdown:

---
layout: post
title:  "Welcome to Jekyll!"
date:   2013-05-09 22:39:53
categories: jekyll update

---

This leads to the post having url /jekyll/update/2013/05/10/welcome-to-jekyll.html, which can be explained by me being in a timezone with offset +0200.

The url I expected to see was /jekyll/update/2013/05/09/welcome-to-jekyll.html.

Changing or removing the time part of the metadata (or adding timezone info) fixes the problem as expected, but it left me puzzled for a moment.

[zachgersh]

by chance, what is your system timezone set to?

[parkr]

He says it's "+0200" above, which is my timezone as well. Central European.

[zachgersh]

Didn't you add specification of timezone to support just this issue?

[parkr]

Yes, but there's an edgecase: if you don't specify the timezone when making posts and pages, it assumes it's UTC, I guess.

[zwippie]

I'm sorry, I should have added that bit of information: System timezone in /etc/timezone is Europe/Amsterdam. To my best knowledge, Ruby uses that info. Also, adding the timezone to the config file did not change the situation. So what parkr says seems to be the case: the time/date is converted to UTC where it probably should not.

[parkr]

i will look into this more, probably something i'd want to make into the gh pages release //cc @benbalter

[zachgersh]

So @parkr and I took a look at this and there seems to be nothing wrong with how the time / date are parsed (it always ends up in your local timezone).

I am not sure how your url would have rolled over like that. We checked to make sure the time didn't default to UTC or have any wonkiness.

Doesn't seem to be anything wrong at present with it.

[zwippie]

@zachgersh I agree with you that no strange things seem to happen in ie. post.rb when it comes to parsing and formatting dates. If no one else experiences this one-day-off error then I guess there is something wrong on my side.

For the sake of completeness:

Linux Debian 6 kernel 2.6.32-5-amd64
rvm 1.15.7
ruby 1.9.3p194
Jekyll 1.01

[zachgersh]

Well, I don't want to claim it is not there just because I didn't experience it 😄

The only thing I could possibly think of is daylight savings having something to do with it but that feels like a stretch.

Just out of curiosity can you double check in your IRB that your offset is what you expect it to be from Ruby?

[zachgersh]

I think we can close this for now @parkr.

@zwippie please reopen if you stumble across this and have new info.

[allxiao]

I've experienced this issue on my first taste of Jekyll today.
The default timezone of my Mac OS X system is set to CST (+0800).

➜  ~  date
Fri Aug  2 17:29:51 CST 2013

The generated example post (by jekyll new blog) have metadata as followed:

---
layout: post
title:  "Welcome to Jekyll!"
date:   2013-07-30 17:57:28
categories: jekyll update
---

And after running jekyll serve, the URL for the post is

http://localhost:4000/jekyll/update/2013/07/31/welcome-to-jekyll.html

If I edit the date of the post in metadata to 2013-07-30 17:57:28+0800, everything works fine.

It seems that Jekyll parses the date in metadata with default timezone set to UTC (if no timezone info is specified in the date string), but then generates the link according to the system default timezone.

It would be better either 1) to generate system timezone aware date string in metadata when running jekyll new blog or 2) to parse the date in metadata with default timezone set to system timezone.

Thanks~

[parkr]

Adding the timezone is a great idea! We also want to create generators which create new posts - we'll add it there as well.

[parkr]

Rel: #1148.

[makkes]

Having to add the timezone to the date metadata is pretty awful. Why do I have to specify it in _config.yml, then? Why not just assume every date without a specified timezone to have the one specified in _config.yml?