Daily #nb-plugin for making daily posts in nb. Modified from the original to title the initial file and make the filename more obviously a daily post.

daily.nb-plugin

#!/usr/bin/env bash
###############################################################################
# daily.nb-plugin
#
# Write to a daily log.
#
# Install with:
#   nb plugin install https://github.com/xwmx/nb/blob/master/plugins/daily.nb-plugin
#
# A plugin for `nb`.
#   https://github.com/xwmx/nb
###############################################################################

# Add the new subcommand name with `_subcommands add <name>`.
_subcommands add "daily"

# Define help and usage text with `_subcommands describe <subcommand> <usage>`.
_subcommands describe "daily" <<HEREDOC
$(_color_primary "Usage"):
  ${_ME} daily [<content>] [--prev [<number>]]

$(_color_primary "Options"):
  --prev [<number>]   List previous days and show day by previous <number>.

$(_color_primary "Description"):
  Add notes to a daily log. When called without arguments, the current day's
  log is displayed. When passed \`<content>\`, a new timestamped entry is added
  to the current day's log, which is created if it doesn't yet exist.

  Previous day's logs can be listed with the \`--prev\` option. View a previous
  day's log by passing its \`<number>\` in the list.

$(_color_primary "Examples"):
  ${_ME} daily "Example note content."
  ${_ME} daily
  ${_ME} daily --prev
  ${_ME} daily --prev 3
HEREDOC

# Define the subcommand as a function, named with a leading underscore.
_daily() {
  # Usage: _daily_show <path>
  _daily_show() {
    local _target_path="${1:-}"

    [[ -n "${_target_path:-}" ]] || return 1

    printf "%s:\\n" "$(_color_primary "${_target_path##*\/}")"

    _show "${_target_path:-}" --print

    return 0
  }

  local _content=("${@:-}")

  local _notebook_path=
  _notebook_path="$(_notebooks current --path)"

  local _target_filename=
  _target_filename="$(date "+%Y%m%d").md"

  local _target_path=
  _target_path="${_notebook_path}/${_target_filename}"

  if [[ -z "${_content[*]:-}"       ]]
  then
    if [[ ! -e "${_target_path:-}"  ]]
    then
      printf "Add the first note of the day: %s daily <content>\\n" "${_ME}"

      return 0
    else
      _daily_show "${_target_path:-}"
    fi
  elif _contains "${_content[0]:-}" \
    "--all" "--ago" "--day" "--days" "--prev" "--previous"
  then
    local _daily_note_paths=()

    _daily_note_paths=($(
      find "${_notebook_path:-}"                                  \
        -maxdepth 1                                               \
        -type     f                                               \
        -name     "[0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9].md"   \
        | sort
    ))

    if ! ((${#_daily_note_paths[@]}))
    then
      printf "Add the first daily note: %s daily <content>\\n" "${_ME}"

      return 0
    fi

    if [[ "${2:-}" =~ ^[0-9]+$ ]]
    then
      local _note_number="${2:-0}"

      if [[ "${_note_number:-}" -ge "${#_daily_note_paths[@]}" ]]
      then
        _exit_1 printf "Not found.\\n"
      fi

      _note_number=$((_note_number + 1))

      _target_path="$(
        printf "%s\\n" "${_daily_note_paths[@]:-}"  \
          | tail -${_note_number:-}                 \
          | head -1
      )"

      _daily_show "${_target_path:-}"
    else
      {
        printf "%s\\n" "${_daily_note_paths[@]:-}"
      } | {
        local _counter=
        _counter=$((${#_daily_note_paths[@]}))

        local               __line=
        while IFS= read -r  __line || [[ -n "${__line:-}" ]]
        do
          _counter=$((_counter - 1))

          {
            _list "${__line}" --no-color
          } | {
            printf "%s %s\\n"                       \
              "$(_color_brackets "${_counter:-0}")" \
              "$(cat)"
          }
        done
      }
    fi
  else
    local _timestamp=
    _timestamp="$(date "+%H:%M:%S")"

    local _formatted_content=
    _formatted_content="$(_join " " "${_content[@]}")"

    local _timestamped_content="[${_timestamp}] ${_formatted_content}"

    if [[ ! -e "${_target_path:-}"  ]]
    then
      _add --content "${_timestamped_content}" --filename "${_target_filename}"
    else
      _edit "${_target_filename}" --append "${_timestamped_content}"
    fi
  fi
}