Move expired sql entries into another database at specific times

I am making a rails website that involves shift management. I am using a separate database (SQLlite3) to archive past shifts because I will need to do operations on future/present shifts and I don't want them slowed down for seldom accessed archives. I want to automatically move each shift to the new database exactly when it ends. I know I can use cron to check every so often but is there a way to do it at the specific time? I don't need exact code just a point in the right direction. Thanks in advance.