if you want to plot times you can use naismiths' rule
walking rate horizontal - fast 5km/hour, average 4km/hour, slow3km/hour, very slow 2km/hour
Uphillrate - fast 900metres / hour = 15metres in 1 min, average 600metres / hr = 10m in 1 minute, slow 300mtrs / hr = 10metres in 2 minutes.
Add 1 minute for every 10 metres of steep descent
Once you work out your walking rate and uphill rate you can add the figures together for your trip and get a rough idea on time. Uphill rate will require close lookign at contours to work out height gained.
Otherwise work it out from experience