… this article deals with one particular and sometimes annoying quirk of Timeshift – it does not allow you to schedule backups at a particular time of day if you use its GUI to schedule backups (this assumes you are not doing hourly backups; in that case you probably want a backup to be made every hour no matter what). Maybe you are using Linux to run a home theater PC – in that case you probably don’t want Timeshift deciding to do a backup during prime time. Or in an office setting, you might not want Timeshift running during your busiest time of day. But Timeshift gives you no way to control that (unless you resort to running it from the Linux command line, and that may have certain other disadvantages). Wouldn’t it be nice to be able to force Timeshift to do its backups in the middle of the night, or at some other preferred time of day?

Well it turns out it is possible. …

Source: How to force Timeshift to schedule backups at a specific time of day – Two “Sort Of” Tech Guys