this happenes when you check in and check out dates fall in different traiff.
For example: if jktdc have offered 10% discount till 31 March and 15% discount from 1st april, and lets suppose your arrival date is 30 Mar and departure is 4th april
hence your arrival and departure dates fall in 2 different traiff, in this case you have to split the booking, you have to make 2 booking one for 30th and 31st march and other from 1st april to 3rd april.