If you could travel into the past or future, is every place you stop the present?
The reason I've been thinking about this is The Doctor can not go into the past to stop The Time War because the Tardis has a built-in safety that doesn't allow travel into the Gallifraen past. And yet, he has been to the Big Bang [Doctor 5] and the end of the Universe [Doctor 10]. Doctor 4 had the chance to destroy the Daleks in "Genesis of the Daleks" but chose not to because of all the races that would ban together in the future. Clearly, he knew the future outside Gallifrey but not of Gallifrey since time is strictly linear there. So, when is it the present for the Doctor?