Or, here's an even better alias.

  alias jim=' \
    journaldir="$HOME/journal" ;   \
    year="`date +%Y`" ;            \
    yearpath="$journaldir/$year" ; \
    [[ -d "$yearpath" ]] || mkdir -p $yearpath ; \
    jfile="log_`date -I`.md" ;                \
    jfilepath="$journaldir/$year/$jfile" ;    \
    header="# log_`date -I`\n\n# Highlights:\n\n" ; \
    [[ -f "$jfilepath" ]] && echo "Opening log: $jfilepath" || { echo "Creating new log: $jfilepath" ; echo -e "$header" >  $jfilepath ; } ; \
    vi $jfilepath ; '

Copy this to your .bash_aliases file. It's fully automatic. It'll create the directories automatically.

This will now create a /home/user/journal/YEAR/journalfile.md. It's now separated by year, so that you can run this forever, and have a maximum of 365 files per year directory.

This is a markdown file. And in the header variable, I had it fill in the new file with some basic headers. You can edit this yourself to add more.

Try it out, and let me know.