If you're not sure about the settings for adjusting the Timer it is best to leave them as the defaults - you can click the "Reset All Settings to Defaults" button to reset them.
These are really just for advanced use. You would need to carry put some benchmark runs to establish what your personal settings would be. For example, run 1 mile on the flat and then 1 mile uphill to see how much longer it takes per metre of ascent. Then calculate how much further you could have run on the flat for that extra time. Do the same for a downhill run.
I have a route (an imported GPX) for a trail run, with a total climb of around 4300 ft.
I am trying to estimate the completion time and have set my estimated average pace. I also ticked "adjust for hills" ... however, I have no idea if the settings are appropriate - for me and/or for running!?
Can someone explain in more detail what the settings mean please.