Central Railway runs Special Trains during Season. You can book tickets in these well in Advance. But the new concept brought by CR GM Subodh Jain is henceforth these special trains will have only tatkal bookings. I will explain with an example.
Take for example WR King 12951 Mumbai Rajdhani and 09005 Mumbai NDLS Rajdhani type.
Mumbai Rajdhani TT is BCT Dep 16:40 NDLS Arr 08:30
09005...
more... Rajdhani Type TT is BCT Dep 19:45 NDLS Arr: 17:35.
The New Concept is 09005 will have only Tatkal bookings plus this train will start after Mumbai Rajdhani say after a 20 min Gap and follow Mumbai Rajdhani TT and will also reach NDLS with same time gap of 20 mins.
CR GM Subodh Jain has sent it to RB for approval.