I dunno.... onions are very slow from seed. I usually plant them in October. They sprout and then go dormant for the winter and start up again in late winter and make onions by July-ish. This is the same schedule as for garlic, which is closely related.
But it is FEBRUARY... If you are talking about starting seeds indoors, if you are in zone5 (I think that would be northern ILL)
you should be starting the cold weather stuff - broccoli, cabbage, cauliflower, kale, celery- and also the stuff I mentioned above that is very slow like lavender, rosemary, parsley, thyme.
If not now, then very soon you would start hot peppers and purple basil, which though warm weather stuff are also pretty slow.
Spring is coming! Time to get started!