Soak the almonds in cold water for at least 8 hours. This will make you have more milk in the end.
Once they have soaked, drain them and put them in a blender and add a liter of water to it. Add the dates and a pinch of salt and the vanilla extract and blend everything together for about 3 minutes. in the meantime prepare a colander with a cheesecloth inside over a big bowl. Once the almonds have sufficiently turned, add it into the prepared colander and let it drain. Once it looks dry, put the corners of the cheesecloth together and squeeze it. You'll be surprised how much more liquid will come out.
You can keep the almond milk in a sterilized jar for about 4-5 days in the fridge.