For 35 years I have kept a digital diary, first on Mac and now on iPad/iPhone. My diary grew out of a UNIX system I developed in the 1980s for reporting programming progress to my supervisors. I keep files with lines beginning in YYYY/MM/DD for sorting and searching. As of today I have 24,390 entries!
Originally I used HyperCard and AppleScript; I made an On This Day script that assembled entries from 1, 5, and 10 years prior and emailed it to me and my husband. Now I use Notes for making daily entries on iPad which I process every month on Mac using BBEdit and AppleScript, the output of which I upload to the cloud for searching on IPad/iPhone using CSV Touch. A cumbersome process. CSV Touch is great for searching, you get instantaneous response and the app spits out just the applicable lines. Although I love CSV Touch, it's not good at sharing data with other apps and I fear the author will someday abandon it.
So, the more I think about it the more I'd like to split the 24,390 lines into 366 day notes.