You guys might have tackled the issue... is there a way to record from a channel that doesn't have their TV programming guide on the grid, just by entering the time in and time out and the number of the channel to record from?
Also, do you have the schedule for the broadcast channels from Israel? I added them through an m3u link but I couldn't find their logo and schedule. I found a way to manually add the logo but not their schedules.
No natively. There are workarounds by manually sending the info for the recording through the command line, but it is unsupported.
See this thread for the details:
Voted. 
Would that work on a Mac too?
I am actually using a Rasberry as my DVR Server
Yes, it works on a Mac. If you follow the thread to the end, you'll see I created a script to make this easier. However, the script I posted will not work as-is, as it assumes you are running it on Linux; the date command on a Mac is very different from the date command on Linux. To adapt the script, see my post here.
If you run the script over SSH on the Pi, then you won't have to change how date works, since it would be using the Linux version. Changes are only needed if you do it from the Mac itself.
I bet the reason it is not officially supported yet is because of metadata match. If you just record a time, there will be no way for it to match to anything and it will be a mess. Since they are working on giving us the ability to manually modify/enter our own metadata, once we have that then a feature like this could exist natively.