Setting OS X Desktop Picture Based on Time of Day

I recently changed jobs (Hello, FireEye!) and was issued a new MacBook Air. I spend a lot of time looking at the screen and was getting bored with the supplied desktop pictures. I also start work very early most days (7am-ish), and thought it would be nice to have a desktop picture that matches the mellow-ness of such an early hour.

Of course, this leads to daydreaming — “scope creep” in professional parlance — and next thing you know, I started thinking “well, maybe I could also set it to show a nice evening-themed picture at night”. Then “maybe I can get it to change both screens” (I use a laptop with an external display).

I also liked the challenge of putting together a script as quickly as possible. (In my off-hours, of course!)

I downloaded some nice wallpaper images from National Geographic, then created six folders that correspond to the major periods of the day: morning (early and late), afternoon (early and late), and evening (early and late). I organized my National Geographic photos into those six folders, based on the mood each photo evokes. For example, this one is an early morning photo.

Then I rolled up my sleeves and got out the trusty old AppleScript Editor. The resulting AppleScript is posted on GitHub, if you’d like to take a gander.

The gist:

• It selects a folder based on the time of day.
• It randomly selects an image from within that folder and displays it as the desktop picture.
• It supports more than one monitor, with an option to either display the same image on all monitors, or display different images on each monitor.

The resulting AppleScript must be run at a regularly scheduled interval. I’m currently using GeekTool to run the script every 15 minutes, but I might eventually switch to a crontab job for less overhead.

Regardless, I’m quite happy with the way it turned out, and have already started daydreaming about other things I can hack together with AppleScript.