how to add date and time into spacemacs' mode line

Question

I usually use Spacemacs in maximized window, thus the date and time presented in mode line is a must.

I understand that spacemacs uses powerline mode to mimic vim, the manuals of both spacemacs and powerline does not tell how to add new section to display additional info (in this case it is date and time).

I have attempted to comprehend the nyan cat code in color layer, but my elisp skill did not satisfy.

Answer 1

To get the time mode, just add (display-time-mode 1) to your ~/.spacemacs configuration.

To get date and time, do this instead

;;display time in powerline
  (spacemacs|define-mode-line-segment date-time-segment
    (shell-command-to-string "echo -n $(date +%k:%M--%m-%d)")
    )
  (add-to-list 'spacemacs-mode-line-right 'date-time-segment)

Source: https://www.reddit.com/r/emacs/comments/3lu414/how_to_add_date_and_time_into_spacemacs_powerline/

I customized mine with this...

  ;; display time in powerline
  (spacemacs|define-mode-line-segment date-time-segment
    (shell-command-to-string "echo -n \"⏰  $(date '+%a %d %b %I:%M%p')\""))
  (add-to-list 'spacemacs-mode-line-right 'date-time-segment)
  )

so now my powerline looks like this

Answer 2

What worked for me was the following.

(spaceline-define-segment datetime
  (shell-command-to-string "echo -n $(date '+%a %d %b %I:%M%p')"))
(spaceline-spacemacs-theme 'datetime)

I had to put that code in user-config section of .spacemacs.

Answer 3

Mine's working great just with:

(setq display-time-format "%H:%M:%S %a,%d %b %Y")

(display-time)                 

Answer 4

Emacs has native time functions: current-time-string and format-time-string. You should just have to eval one of those - i.e. (current-time-string). This works fine for telephone line, so I would assume it's the same for powerline/spaceline/etc.

E.g.

(spaceline-define-segment datetime
  (current-time-string))
(spaceline-spacemacs-theme 'datetime)

Here's the doc for format-time-string if you want something other than the default:

https://www.gnu.org/software/emacs/manual/html_node/elisp/Time-Parsing.html