Takes a text file listing daily log entries, and imports them into Day One. With the latest version of Day One, the command line tools are available separately. Download and install it from their Tools page.
ruby parse.rb <path to file>
Each day should begin with the date in yyyy.mm.dd format. I include the day of the week after that, but the script will ignore anything after the date. The lines following it are presumed to be the details of the day's goings-on. I start mine with two spaces and leave a blank line between days, but again, the script will ignore this. As far as the script is concerned, a new day begins every time it finds a line beginning with the yyyy.mm.dd format.
2012.05.17 Thu
Met with Steve after work
Caught up on email
2012.05.18 Fri
Had dinner with the Smiths
Took a cab home and watched Iron Man 2
2012.05.19 Sat
Helped Steve and Jenny move to their new place
Took a nap
Quiet evening
2012.05.20 Sun
Went to the farmer's market in the morning
Had a late lunch at Founding Farmers
Went for a walk