i understand journaling to be about today, not something eventful in the past. that prompt i'd be tempted to answer with a multi page essay.
the key for me for journaling is habit. the habit to do this every day, and not to skip. the prompt doesn't matter. i just write about anything noteworthy from that day.
with a plain text editor, into a file.
it's not ideal though. it's the last thing i do before going to sleep, and once in a while i miss an entry. and on some days, i feel there is nothing to write.