Hi, I somehow solved the problem. It is not a great solution but it will do.
I used the htsp library provided with tvheadend at lib/py/tvh
Use the attached tvh.tar.gz
you need python to run the script
/path/to/create_dvr.py channelName/ID Title StartTime StopTime weekDays
channelName/ID : channel Name or its Id
Title          : Title of the recording
StartTime      : Start Time in 24:00
StopTime       : Start Time in 24:00
Weekdays       :
                 U Sunday
                 M Monday
                 T Tuesday
                 W Wednesday
                 R Thursday
                 F Friday
                 S Saturday
                 
example:
 ./create_dvr.py "Al Majd Scientific Channel" Otrooja 14:00 14:30 UMTWRS
 or
./create_dvr.py 387 Otrooja 14:00 14:30 UMTWRS
ToDo:
Modify create_dvr.py:
    change user to any tvheadend user
    keep passwd empty otherwise it will create an error when adding a dvr
    Change/add channel names in getChannelId and their id.
    
To make weekly schedule modify weekly_schedule to include all the dvr for the week
To make it automatically added to tvheadend you can use cronjob with weekly_schedule
There is a bug in the htsp python library when trying to use a password with add dvr,
 so you need to create any empty user
 for the script to run normally but for security,
 make the prefix for the  user 127.0.0.1/32 and/or your pc Ip address/32.