Oh the pressure! Hope you like it!
The scheduling is a joke. Given the earlier matches, I'll be surprised if this match starts before 4 pm, also the weather forecast is for light rain/intermittent showers during the afternoon, so there could be rain delays.
As for the match - Andy is desperate to win a medal for GB. Djokovic is desperate to improve on his bronze in Beijing for Serbia. Andy will get great crowd support which should lift him. Djokovic says he won't be fazed by playing in front of such a partisan crowd. The only common ground (literally) is that it's the first time they've played each other on grass in a serious tournament.
Taking this, and the comments in the various posts, into account, I'd say this match has the potential to go either way, but Andy has to actually BELIEVE he can win it. Wanting to do so is one thing, believing he can do it is quite another.