<< >> - jump in 2 hour steps
To jump 24 hours you have to press and hold the left/right arrow cursor control, an overlay will then appear with dates, highlight the date required and press OK, guide will 'jump' to selected date.
Or
As added in an update press + and highlight jump to date.
Page up/down - as usual for Humax use the CH up/down key.
You can 'jump' to a specific channel by entering the channel number.