You want to give at least a two weeks' notice. Illinois is an at will state so unless you signed a contract, you don't even have to give them a notice.Atwill employees can quit at any time with no notice. However, it is customary to give two weeks notice (or even more if you hold a high level position). Please accept my sincerest apologies for being unable to provide you and the Davidson Team with a notification that includes a minimum two-week notice. Learn how to write a short notice resignation letter with this stepbystep guide, template and examples of formal resignation. The company is not obliged to give to an employee any advance notice before resigning. However, in some cases, two weeks' notice may be given. Procedure. Learn how to craft a professional resignation letter without notice with our guide. This article will guide you through creating an effective notice letter, helping you leave on good terms and with confidence.