One of the plus sides of being an author is the power to re-arrange aspects of the world in the way you want them. My particular favourite is the weather. If you want snow, or rain, or a long hot summer, you can have it. (I tend to go for the latter, personally) You do have to observe some natural laws, of course. Snow in the UK in July might be pushing it a bit.
Geography can be a little more tricky. You can invent your own, or interfere with what really exists, but the reader has to be prepared to go with you on that. Willing suspension of disbelief. Some things are difficult. Moving mountains around, having the whole of the south of England covered in forest, that sort of thing. There is only so much latitude for invention. I'm currently incubating a Welsh Village that doesn't appear on any maps, which is a lot of fun, but it will have to be based in an element of reality. Sort of, says she, blithely. We'll have to see how that turns out.
Time, unless you are writing time slip, is not really to be messed with. If it takes two hours to make a car journey, for instance, there is no way you are going to get the heroine there any faster. History can be difficult to re-organise too. Maybe some jiggling at the edges, conflation of events, a little reorganising of the order on occasion. But it is going to be hard to reschedule the battle of Hastings to 1067, however much you want to.
If you are into supernatural, paranormal or fairy tale, then things are a lot more fluid, but even there things have to make a certain sense, at least within the story itself.
This power thing occurred to me last week when I reorganised the train timetable to suit my convenience. I discovered I'd managed to have my hero on a journey running backwards from the route he would have taken - a salutary reminder that you really do have to check everything. Something had to be done, so for once engineering works came to the rescue. I shut the line he was on for emergency work and sent him across country on an alternative route, to get him where I wanted him to be. Maybe it wasn't the way the train company would have organised it, but it was plausible, so hopefully that is enough to get by. Took a bit of figuring out, mind you. With power comes responsibility.
It's power, but it does have to make sense. The reader has to be able to accept what you have done.
But I do love having control over the weather.