Library refresh API

My library contents changes often, but refreshing every 5 minutes uses additional resources which could be performing other functions. Furthermore, setting a refresh interval from an arbitrary point when the process was first started doesn't let me pinpoint what time of day the refresh is performed.
Ideally, I would like to use cron to run a shell script that refreshes the library when I choose. In Windows this could be done using Scheduled Tasks and an exe.
Thanks.
Ideally, I would like to use cron to run a shell script that refreshes the library when I choose. In Windows this could be done using Scheduled Tasks and an exe.
Thanks.