How is "Time held" calculated?
Since the exact time a zone was lost is not available, the approximate time is calculated based on the PPH for the zone and how much accumulated points you have gained from the zone. For zones with low PPH that you held for a short time there will be a larger error compared to zones with high PPH that you held for a long time.
Why is there a questionmark in the column "Time held"? Zones with 250 (300 if taken from Neutral) takepoints have zero PPH (if it didn't turn into a 170/2) and it's not possible to calculate the time held in that case.
Why are some zones green and some red on the map? A zone turns red if you have lost it during the session. Because the time of the loss is only an approximation the map might not reflect the situation IRL exactly. Note that, as for now, 250/300 zones counts as an immediate loss.
Who took zone X from me? The information which turfers took zones from you is unfortunately not available in the warded session data.
If I have spotted an error on your page or if I have a suggestion or question how do I get in contact? I might set up an issue tracker in the future but currently you can post questions/give feedback etc in this facebook thread https://www.facebook.com/groups/turfgame/permalink/1016592501713844/