Cbr12, I have come bearing gifts...
I have been mucking about with my countdown timer and managed to implement what I think you're after... Quite a nifty little feature I think... The patch is here: http://www.rockbox.org/tracker/task/6297
and here's a description of what it does....
All timer settings (including filesplit etc) are under a menu in the recording settings called Timer options.
Setting "Record repeat every.." you can set a time for a repeated recording eg. set it for 1 hour and a recording will start every hour from when you start the first recording. This needs to be used in conjunction with the "Split time" option.
"Split measure" and "What to do.." are automatically Â set to 'time' and 'stop' respectively when "Record repeat every.." is set.
You need to set a "Split time" that is less than your "Record repeat every.." setting.
First set "Record repeat every.." to 12 minutes
then "Split time" to 5 minutes.
Then go into the recording screen and press record
This will result in a 5 minute recording and then a 7 minute pause, then another 5 minute recording and 7 minute pause..etc etc until you stop the recording or pause the timer.
This can also be used in conjunction with the countdown timer to start the first recording at a specific time.
Hope that does the trick, I'll be interested to know if it works ok for you.