oh yes there definitely is a reason why the GR comes back on saturday. if it came back on sunday, then a lot of people will find it useful and hence more people will use the train. this will drastically reduce the number of people who go by bus which in turn will do no justice to all the money taken by railway babus from the bus lobby. hence in everyone's interest (except passengers, it was decided to run the GR on friday at an odd time and then return it on saturday itself(