A very simple time tracking tool for the command line.

.bashrc

# Time Tracking Tool
####################
# Simply writes dates/times/comments in a file.
# Each week has it's own file (e.g. ~/.ttt/2019-01.txt).
#
# ttt <comment>: add entry to current week's file
# tttt: output current week's file content with cat
# ttte: edit current week's file with vim
# tttp: pause
# ttts: sum times

ttt() {
        mkdir -p ~/.ttt
        file="/home/$USER/.ttt/$(date +"%Y-%W").txt"
        echo `date '+%Y-%m-%d %H:%M'`" | "$* >> $file
        printf "Added time tracking entry:\n"
        tail -1 $file
}
alias tttt='cat ~/.ttt/$(date +"%Y-%W").txt'
alias ttte='vim ~/.ttt/$(date +"%Y-%W").txt'
alias tttp='ttt pause'
alias ttts='awk '"'"'BEGIN{ FS=" *\\| *" }
function to_epoch(s,   cmd, out){
  cmd = "date -d \"" s "\" +%s";
  cmd | getline out; close(cmd);
  return out + 0;
}
{
  dt  = $1;                 # "YYYY-MM-DD HH:MM"
  key = $2;                 # alles hinter dem |
  gsub(/^[ \t]+|[ \t]+$/, "", key);

  t = to_epoch(dt);

  if (have_last && last_key != "pause")
    times[last_key] += (t - last_time);

  last_time = t;
  last_key  = key;
  have_last = 1;
}
END{
  for (k in times)
    printf "%-20s %.2f Std\n", k, times[k]/3600;
}
'"'"' ~/.ttt/$(date +"%Y-%W").txt'