I'm using Jekyll, and Jekyll's post needed a date time for metadata like below, it would be better if we have a shorthand for date time insertion.
---
layout: post
title: "pandemic"
date: 2021-11-17 19:19:26 +0800
---
in my .vimrc
...
" insert current date time
" e.g. 2021-11-17 19:19:26 +0800
nnoremap <F5> "=strftime("%Y-%m-%d %H:%M:%S %z")<CR>P
inoremap <F5> <C-R>=strftime("%Y-%m-%d %H:%M:%S %z")<CR>
...
Since Vim already had a build-in function strftime so it can be done very easily.
Now on Vim editor, I can insert date time by F5.