Note that my guide doesn’t work with recent openHABian builds unless you generate SSH keys. There’s a discussion in the comments, but I never got around to implementing it as I rarely need to reboot openHAB these days.
The solution in that thread was to upgrade your system so that you would have more time-based threads. If you’re running more than 10 time-based rules (which I assume to be the case), then it’s not a problem with the system; it’s a problem with your approach. Instead of asking openHAB to do more than it’s capable of doing, let’s rethink how your rules work.
So the question is, how do you reduce the number of time-based rules you need? Something that many of us do is use the Astro binding to identify time of day (sunrise, sunset, etc.) and trigger rules on those changes. That enables things like lights and rollershutters to adjust with the seasons, which I personally find to be preferable over “always do this at 7:00AM”.
If you’re committed to things happening at specific times, then you could set up a time-based rule that updates a proxy item, and trigger all of your other rules based on the proxy item changing. Then you’d only need one time-based rule. Or have a few different rules/proxies if you want to group things together. Just don’t go over 10 and you should be fine.