A small script that manages your diary. Put it into a folder, initialize a git repository there and push it to a remote. The rest will be done by the script.

journal.sh

#!/bin/sh

# Get your own path
path=$(dirname $(realpath $0))

# Make sure that git uses the path of the script and not the current directory
git="git --work-tree=$path --git-dir=$path/.git/"

# Get today's date
day="$(date +'%d')"
month="$(date +'%m')"
year="$(date +'%Y')"

# Parse arguments and replace the dates accordingly

if [ "$#" -eq 1 ]; then
  if [ "$1" = "y" ]; then
    day="$(date -d "yesterday 13:00"  +'%d')"
    month="$(date -d "yesterday 13:00"  +'%m')"
    year="$(date -d "yesterday 13:00"  +'%Y')"
  elif [ "$1" = "--help" ]; then
    cat << EOF
usage: $0
       (to write today's entry)
  or   $0 y
       (to write yesterday's entry)
  or   $0 [day]
       (to work with the entry of entry a specific day)
  or   $0 [day] [month]
       (to work with the entry of entry a specific day and month)
  or   $0 [day] [month] [year]
       (to work with the entry of the given date)

Missing arguments will be replaced by the current date.
For example:
  Executing '$0 01' would open day 01 of the current month and year.

Uses your \$EDITOR variable to edit entries.
It should be set in your .bashrc, or .zshrc, ...

Report bugs to: [email protected]
EOF
    exit 0
  else
    day=$1
  fi
elif [ "$#" -eq 2 ]; then
  day=$1
  month=$2
elif [ "$#" -eq 3 ]; then
  day=$1
  month=$2
  year=$3
elif [ "$#" -gt 3 ]; then
  echo "Invalid amount of parameters!"
  exit -1
fi

# Make sure the directory exists
mkdir -p $path/$year/$month/
fullpath="$path/$year/$month/$day"

# Pull to make sure no foreign edits were missed
echo "Updating remote changes..."
git --work-tree="$path" --git-dir="$path/.git/" pull
echo

# Edit the actual file
$EDITOR $fullpath

# Check if file exists before doing other checks
if [ ! -f $fullpath ]; then
  exit
fi

# Determine if the file is new and set commit message
$git add $fullpath
line="$($git status --porcelain | grep $year/$month/$day)"
$git reset --quiet -- $fullpath

if [[ "${line:0:1}" == "A" ]]; then
  message="Add"
elif [[ "${line:0:1}" == "M" ]]; then
  message="Edit"
else
  echo "No changes."
  exit
fi
message="$message entry for $day.$month.$year"

# Ask the user if the changes should be pushed
if whiptail --yesno "    Done?" 8 20;then
  # Do a spellcheck
  aspell --personal="$path/.aspell.en.pws" --repl="$path/.aspell.en.prepl" --dont-backup check $fullpath

  # Do the git stuff
  $git add $fullpath
  $git add $path/.aspell.*
  $git commit -m"$message"
  echo "Uploading..."
  $git push
fi