Calculate total drawing time in Krita. run: krita-drawing-time.sh /path/to/your/kra-files

krita-drawing-time.sh

#!/bin/bash

if [ -n "$1" ]
then
  cd "$1"
fi

readableTime() {
  value=$1
  res="$(($value % 60))s"

  value=$((value / 60))
  if [ $value -gt 0 ]
  then
    res="$(($value % 60))m $res"

    value=$((value / 60))
    if [ $value -gt 0 ]
    then
      res="$(($value % 24))h $res"

      value=$((value / 24))
      if [ $value -gt 0 ]
      then
        res="${value}d $res"
      fi
    fi
  fi

  echo "$res"
}

getTagValue() {
  sed "/<$1>/"'!d'";s/.*>\(.*\)<.*/\\1/" <<< "$doc"
}

declare -a timings

for filename in $(find * -type f -name '*.kra')
do
  doc=$(unzip -p "$filename" documentinfo.xml)
  title=$(getTagValue title)
  creationDate="$(getTagValue creation-date | sed 's/[^0-9]//g')"
  editingTime="$(getTagValue editing-time)"
  [ -n "$editingTime" ] || editingTime=0
  echo -e "$filename\t$title\t$creationDate\t$editingTime\t($(readableTime $editingTime))"

  existingTime="${timings[$creationDate]:-0}"
  if [ -z "$existingTime" -o "$existingTime" -lt "$editingTime" ]
  then
    timings[$creationDate]=$editingTime
  fi
done

total=0
for key in ${timings[@]}
do
  total=$(($total + $key))
done

echo -e "total time spent=$total seconds ($(readableTime $total))"

Calculates total time for all drawings in directory. If directory name is omitted current directory will be used.

bash krita-drawing-time.sh ~/Pictures