Repeating formula help for a newbee

Hello all! Am new to this forum and was hoping anybody could help me with what should be a very simple query - i'm just not that good at excel. I have been trying to update a holiday form and could not work out how to do a recurring formula for the 'days left this year' forum. When i try and drag the formula for the correctly entered first cell it does not repeat to reflect the right figure.


Starting total 2014/15 Date taken Number of working days
From To Days taken Total this year Days left this year
37.5 22-Apr 25-Apr 4 4 33.5
28-Mar 28-Mar 0.5 4.5 29
07-Jul 11-Jul 5 9.5 24
33.5
0
0

Any help?

With thanks,

NewbeeElly