GM
When I write my books I start by writing my treatment, which is a summary of what my story is about, and I use it as a guide.
Readers will certainly want to know when your story is taking place, particularly if it's a historical novel. There are ways that you can let them know it's 1941. If your story is set in the United States, the characters will be aware of the fact that Europe has been at war for nearly two years. What is their perspective on these events? If your story is set in Europe, your characters will, no doubt, be dealing with the war and its effects on their daily lives. How are they coping? Rather than open with a boring narrative, such as, "It was the year 1941, and Joe was..." you could, instead, have your characters discussing the events in Europe early in your story, (as in the first chapter), so your readers know what time period your story is set in.
Even if you're writing fiction, you will need to research the time period in which your story is taking place. Readers can by very savvy, and if you're writing historical fiction, rest assured you will have readers who have studied whatever time period your story takes place in, and they will be familiar with that history. Make sure you are as historically accurate as possible.













