.vimrc

nnoremap <Space>gn :<C-u>w<CR>:Git now<CR>
nnoremap <Space>gN :<C-u>w<CR>:Git now --all<CR>

git-now

#!/bin/sh

PREFIX="from now"
MESSAGE="[${PREFIX}] `date +\"%Y/%m/%d %T\"`"

if [ $# -eq 0 ]
then
    git add -u
    printf "${MESSAGE}\n\n%s" "`git diff --cached`" | git commit -F -
elif [ $1 != "--rebase" ]
then
    if [ $1 != "--all" ]
    then
        git add $@
    else
        git add -u
        git add .
    fi
    printf "${MESSAGE}\n\n%s" "`git diff --cached`" | git commit -F -
else
    FIRST_NOW_COMMIT=`git log --pretty=oneline --grep="${PREFIX}" | tail -n 1 | cut -d " " -f 1`
    INITIAL_COMMIT=`git log --pretty=oneline | tail -n 1 | cut -d " " -f 1`

    if [ ${FIRST_NOW_COMMIT} != ${INITIAL_COMMIT} ]
    then
        git rebase -i ${FIRST_NOW_COMMIT}^
    else
        WORKING_BRANCH=`git branch -l | grep "*" | cut -d " " -f 2`

        git checkout ${FIRST_NOW_COMMIT}
        git commit --amend
        git rebase --onto HEAD ${FIRST_NOW_COMMIT} ${WORKING_BRANCH}
    fi
fi

git-now.el

;;; git-now.el - Call "git now" command

(provide 'git-now)

(defun now ()
  (interactive)
  (call-process "git" nil "*git now*" nil "now")
  (pop-to-buffer "*git now*" t nil)
  (other-window -1)
  (message "git now!"))

git-now.rb

require 'formula'

class GitNow < GithubGistFormula
  url 'https://raw.github.com/gist/878015/8a7158b2bfce40415b3a0394afd45c442addfe06/git-now'
  md5 '144c3759343e59187dffd8a7c4cf61a2'
  homepage 'https://gist.github.com/878015/'
end

update

#!/bin/sh

PREFIX="from now"

if [ ! "`git log --pretty=oneline $3 | head -n 1 | grep "${PREFIX}"`" ]
then
    exit 0
else
    echo "error: There are tmp log messages in the received objects." 1>&2
    echo "error: Change these messages by 'git now --rebase'." 1>&2
    exit 1
fi