A flaw in adding entries directly rather than via DayOne's cli tool is likely breakages when things (file formats, locations etc) change. Looks like this has happened with the new update -- at least my gitlogger suddenly isn't adding anything. Haven't had a chance to look at why yet. I did think of quickly editing gitlogger.rb to use the cli tool instead, but the new cli tool is broken (on my system it segfaults). Probably just as well, as I really should do some real work today rather than entertain myself with this ...
You could also use a post-commit hook in your git template directory so you don't have to run anything nightly and it will automatically work for all new repositories
Right, and I did that for a while, but I swamped my log with entries. I want to hand pick which repos are logged, and I like having one log message per day with each repo's commits grouped together. I played with post-commit on tag commits and try to curate things a little more, but in the end I just wanted to not have to think about anything beyond adding the repo to a list and letting everything else go, while still maintaining an orderly log in Day One. Thus, the script :).