Years ago, Brett Terpstra wrote a set of VoodooPad Log Navigation Plugins, which were written in Lua and assisted in opening pages in a VoodooPad document based on the current date. Lua was taken out in VP5, but someone mentioned the older scripts on the forums and I've updated them to work in JSTalk.

You can grab them from github: Go to Next Day.jstalk, Go to Previous Day.jstalk, and Go to Today.jstalk