(7th Cir.2001). There can be no set legal rule for determining whether an adverse employment action falls “close on the heels” of protected activity because such a determination “depends on context.” Loudermilk, 636 F.3d at 315. Of course, “[t]he closer two events are, the more likely that the first caused the second.” Id. But it is clear from our case law that the time period between the protected activity and the adverse action must be “very close.” Id. (citing Clark Cnty. Sch. Dist. v. Breeden, 532 U.S. 268, 273, 121 S.Ct. 1508, 149 L.Ed.2d 509 (2001)). For an inference of causation to be drawn solely on the basis of a suspicious — -timing argument, we typically allow no more than a few days to elapse between the protected activity and the adverse action. See, e.g., id. at 314-15 (<HOLDING>); Casna v. City of Loves Park, 574 F.3d 420,
holding that a 17 month time period between the employees protected speech and his termination could not support an inference of causation holding that a worker who handed his supervisor a note that complained of workplace discrimination and was immediately fired had established an inference of causation by way of suspicious timing recognizing that a vital fact may not be established by piling inference upon inference holding that proof that an employer fired an employee three months after the employee filed a charge of discrimination sufficed to state a prima facie case of causation holding that where the individual who fired the plaintiff is the same individual who hired him less than six months earlier with full knowledge of his age a strong inference exists that discrimination was not a determining factor for the adverse action taken by the employer