While you are banging out a first draft you will be tempted to include specific dates, events that happened or will happen in your novel, names, etc. You might even feel the need to include something fictional informed by something that actually happened. You might want to know what Jack would be wearing as he watched the Berlin Wall come down. So you will feel justified in stopping the writing to go look things up, like what time of year the wall came down and what was the weather like. This is not writing. This is editing in lieu of writing. It is also premature.
You don't even know yet if you are going to keep the sentence that refers to Jack being on the campus at Kent State when the shootings occurred in your final draft. So why stop creating in your urge to look up the date to be accurate in a passage that may later be cut?
Instead, when you run across a need to be specific write the sentence and simply insert the letters TK in the space of the unknown specific. Then, after you have decided to keep that part of the story, look up the specific you need and replace the TK with the number, name, etc.
One other thing, using the letters TK (to come) makes searching your manuscript for those letters easier because they almost never appear together in the English language.