Yes you can prepare a meatloaf the day before and then wait too cook it the next day or go ahead and cook the meatloaf the day before and then refrigerate it and then place the meatloaf in the oven the next day to reheat it.
I've prepared meatloaf dishes before and left them uncooked and then covered the meatloaf and refrigerated it.
Then the next day when I was ready to cook it I just took it out of the refrigerator and baked the meatloaf for 1 hour and 30 minutes.
That way is was fresh but was already prepared.
When you cook a meatloaf you should cook the meatloaf uncovered for best results.
You can cook the meatloaf covered but it will not cook as good so leave the meatloaf uncovered while it's cooking.
Cooking a 2lb meatloaf in the oven at 350 degrees F takes 1 hour and 30 minutes depending on how well done you like your meatloaf.
For me a 2lb meatloaf cooked in the oven at 350 degrees is fully done after being in the oven for 1 hour and 30 minutes.
Meatloaf is best when cooked uncovered so be sure to leave the meatloaf uncovered while it's cooking in the oven.
Also for a good meatloaf eggs are necessary to add to the meatloaf.
The eggs add flavor to the meatloaf as well as help the meatloaf bind together so that the meatloaf doesn't fall apart when you remove it from the oven or cut it.
You could cook meatloaf without the eggs but it won't turn out as good.
Mayonnaise can be substituted for the eggs in meatloaf since mayo contains eggs.
When making a good meatloaf eggs are required to make the meatloaf turn out properly.
Eggs in meatloaf help the meatloaf bind together so it doesn't fall apart and also the eggs add flavor, richness, and moisture to the meatloaf.
If you don't add eggs to the meatloaf the meatloaf will fall apart and won't turn out as good.
So you should always add eggs to the meatloaf recipe if you want to make a good meatloaf.
You can use mayonnaise as a substitute for the eggs in meatloaf since mayonnaise contains eggs and will help the meatloaf bind and turn out good.
I've ran out of eggs before and used mayonnaise when making the meatloaf and it worked out just fine.