This may be the hard way, but I use the LJ download utility to store a month's worth of posts in a text file on my computer, and then I use the Windows Find tool to find the files that have a certain unique phrase or word in them. Then, inside the file, I use Find to locate the word or phrase. That shows me the date of the entry, since that info is downloaded as well and separates the entries.
no subject
Date: 2004-11-12 08:28 pm (UTC)