I understand from this thread that the time of eMC’s daily back-up schedule (which demands some CPU power) can be customised, but I wouldn’t call this a very flexible procedure.
Otherwise, there are several threads that discuss using a “Task Scheduler”, which looks like a Windows app. On this Mac I use CCC, which is kind to the CPU, for all backups. So the question would rather be this one: can CCC’s raw backup of ~/Library/Application Support/eM Client (here: 6-7 Gb) be used on a par with eMC’s own zip file (≈2.2 Gb), or should I just zip CCC’s back-up in order to restore? And: will it make a difference whether CCC backs eMC’s data up while eMC is running, or should it be closed for the backed-up files to be usable?