Best way to change date format in Writer Joomla template

I want to change the date format to y-m-d in the article and sidebar list, etc.
Please let me know which config or file should be modify.
Cheers.

Hi,
do you mean default articles or inside K2 items?

BTW
why you need year as a first item, you're building a historical website?

==SIDEBAR==
1) Find module "New Posts"
2) Edit this settings - change d->Y order
3) Save changes

===DATE in K2 items===
Edit this file:
templates\gk_writer\html\com_k2\templates\default\item.php

Line 137:

<?php echo JHTML::_('date', $this->item->created, 'l, j F Y'); ?>

Read about PHP date rules.

BTW
date of K2 item modification (at the bottom) is taken from K2 translation language file and string "K2_DATE_FORMAT_LC2"

Thank you.
I have finished the modification for K2 items and side bar list.
We are usually using Y-M-D date format in Japan.

Writer template looks very simple, but really multipurpose and high-functioning.

Cheers.

Writer template looks very simple, but really multipurpose and high-functioning.

Thanks, please when you will finish add your website here: https://www.gavick.com/forums/member-sites.html

Arigatou (ありがとう)

I published the site
jweb.asia

Ok, I will check and review. Thanks