From the FGW website :

20:03 Gatwick Airport to Reading due 21:20
This train has been revised. It will additionally call at: Ash, Farnborough North, Sandhurst and Crowthorne.

19:34 Reading to Gatwick Airport due 20:50
This train has been revised. It will additionally call at: Crowthorne, Sandhurst, Farnborough North, Ash and Shalford.

20:08 Shalford to Reading due 20:58
This train has been cancelled. This is due to a member of train crew being unavailable due to sickness.

19:04 Reading to Shalford due 19:54
This train has been cancelled. This is due to a member of train crew being unavailable due to sickness.

17:03 Gatwick Airport to Reading due 18:28
This train has been revised. It will additionally call at: Betchworth, Dorking West, Shalford, Sandhurst and Crowthorne. This is due to a member of train crew being unavailable due to sickness.

16:34 Redhill to Reading due 17:53
This train has been cancelled. This is due to a member of train crew being unavailable due to sickness.