210 F.3d 776 (7th Cir. 2000)
Julie A. RAGER, Plaintiff-Appellant,v.DADE BEHRING, Inc.,    Defendant-Appellee.
No. 99-1400
In the  United States Court of Appeals  For the Seventh Circuit
Argued December 9, 1999Decided April 10, 2000

Appeal from the United States District Court  for the Eastern District of Wisconsin.  No. 98 CV 0670--John C. Shabaz, Chief Judge.
Before Posner, Chief Judge, and Coffey and Manion,  Circuit Judges.
Posner, Chief Judge.


1
The Family and Medical  Leave Act entitles an eligible employee to up to  12 weeks of leave during any 12 month period  because of "a serious health condition." 29  U.S.C. sec. 2612(a)(1)(D). The employer may  require certification from the employee's  physician (or other health care provider) that  the employee indeed has such a condition, 29  U.S.C. sec. 2613(a), but if he does so he must  (if the health condition was unforeseeable) give  the employee at least 15 calendar days in which  to submit it. 29 C.F.R. sec. 825.305. (The  employer can fix a more generous deadline if he  wants, 29 U.S.C. sec. 2613; 29 C.F.R. sec.  825.305(b)--can, indeed, if he wants, dispense  with the requirement altogether. See Thorson v.  Gemini, Inc., 205 F.3d 370, 380-81  (8th Cir. Mar. 3, 2000).) Although the  regulations contain a sample certification form,  29 C.F.R. sec. 825 app. B, they do not require  the employer to use it; but the employer is  required to notify the employee promptly and in  writing of the 15 day deadline and the  consequences of not complying with it. sec.sec.  825.301, .305. This suit alleges a violation of  the 15 day rule. The district judge granted  summary judgment for the defendant, and so we  must construe the facts as favorably to the  plaintiff as the record permits.


2
On December 15, 1997, Julie Rager, an FMLA-  eligible employee of Dade Behring, became  scheduled to have surgery a week later to excise  an infected gland. She reported her impending  absence for the surgery to her immediate  supervisor the same day, and three days later  discussed the matter with both her supervisor and  a member of the company's human resources staff.  She was told she'd be eligible for regular sick  leave, or for paid short-term disability leave  once she had 15 continuous days of absence, and  she was given a form to complete if she thought  she would qualify for the disability leave. The  form required medical documentation. It was also  explained to her that she might be eligible for  longer, though unpaid, leave under the Family and  Medical Leave Act, and so she was given a  "Request for Family Leave" form as well and told  that if she decided to seek family leave she  would have to fill out still another form, namely  a "Certification of Health Care Provider" form.  She was not given that form, though it was made  clear to her that she couldn't receive either  short-term disability leave or family leave  without medical documentation.


3
She dropped off her completed "Request for  Family Leave" form on December 20 but didn't  provide any medical documentation. The surgery  was performed as scheduled on December 22, and  the following day, still not having received any  medical documentation from Rager, Dade Behring  sent her a certified letter repeating the  requirement of medical documentation and pointing  out that the documentation required by the short-  term disability form would suffice. The December  23 letter further informed her that unless she  submitted the required documentation by January  12 she would be fired because of the number of  unexcused absences from work that she would have  accrued by then.


4
On December 29 the company sent her the  "Certification of Health Care Provider" form  because she was "requesting a medical leave under  the Family and Medical Leave Act." A letter sent  her two days later reiterated that she must  submit any required medical documentation by  January 12. The deadline passed without her  responding, and so she was fired.


5
Rager argues that the 15 day period of notice to  which the Act entitled her began to run on  December 31 because that's when she received the  "Certification of Health Provider" form; and she  was terminated fewer than 15 days later. The  company argues that the 15 day period began when  Rager requested family leave on December 19, and  so ended well before January 12. Neither is  correct. Remember that the Act does not require  the employer to request medical documentation on  a particular form. All that is required is that  the employee be informed in writing that he or  she has 15 days in which to submit proof of a  serious health condition, and of the consequences  if it is not submitted within the deadline, which  in this case was termination because in the  absence of an entitlement under the Family and  Medical Leave Act the plaintiff had no excuse for  being absent from work from December 22 on.


6
She was never told in writing in so many words  that she had 15 days to submit the medical  documentation required for family leave, and it  is disputed whether she requested family leave on  December 19. But the December 23 letter, by  giving her a deadline of January 12 for  submission of all required medical documentation  whatever form of leave she was seeking, gave her  all the information that the regulations required  her to have, as well as more time to submit the  documentation than the law requires. She had been  told that the medical documentation required for  short-term disability leave would suffice for  family leave as well and had been given more than  15 days to furnish that documentation. She knew  everything that the Act required that the  employer tell her.


7
No doubt, however, like most other limitations  periods, the 15 day deadline for submitting  medical documentation, or whatever longer  deadline the employer fixes, can be tolled, for  example by conduct by the employer that is deemed  to equitably estop him to plead the expiration of  the deadline as a defense to liability under the  Act. Had Dade Behring told Rager to forget about  the January 12 deadline it had set--told her that  she didn't have to submit her medical  documentation until January 13--it could not have  fired her for failing to submit it by January 12.  Rager mentions equitable estoppel on one page of  her brief, but has made no effort to establish  its elements, and it is unlikely that she could  do so. It had been made clear to her at the  outset that she had to furnish medical  documentation by January 12 or lose her job. And  when it sent her the "Certification of Health  Care Provider" form, Dade Behring did not say or  hint that she had additional time to complete and  submit it. She doesn't even argue that she relied  on her (mis)understanding of the law as giving  her 15 days from the receipt of the form, or that  she even knew of such an entitlement. Yet without  reliance both actual and reasonable, there can be  no finding of equitable estoppel. Level 3  Communications, Inc. v. Federal Ins. Co., 168  F.3d 956, 959 (7th Cir. 1999); Hentosh v. Herman  M. Finch University of Health Sciences/The  Chicago Medical School, 167 F.3d 1170, 1174 (7th  Cir. 1999); Athmer v. C.E.I. Equipment Co., 121  F.3d 294, 296-97 (7th Cir. 1997); Paramount  Aviation Corp. v. Agusta, 178 F.3d 132, 147 n. 12  (3d Cir. 1999).


8
Another tolling provision that might come into  play, equitable tolling, does not require any  misleading conduct by the defendant, only that  the circumstances be such that the plaintiff  could not reasonably have been expected to act  within the deadline. E.g., Taliani v. Chrans, 189  F.3d 597 (7th Cir. 1999); Athmer v. C.E.I.  Equipment Co., supra, 121 F.3d at 297; Santa  Maria v. Pacific Bell, 202 F.3d 1170, 1178 (9th  Cir. 2000); Smith-Haynie v. District of Columbia,  155 F.3d 575, 579 (D.C. Cir. 1998). This tolling  provision is actually in the regulations, 29 CFR  sec. 825.305(b), and so by implication equitable  estoppel is as well, which is merely an  aggravated form of equitable tolling. But  equitable tolling is not argued and would not  avail Rager if it were. She has given no reason  why she could not have submitted the required  medical documentation by January 12, or for that  matter on the day of the surgery, December 22,  when the surgeon told her she couldn't return to  work for four weeks. There is no suggestion that  during the period of her convalescence following  the operation she was physically or mentally  disabled in the slightest from attending to the  paperwork requirements incidental to the  operation. Even so, the form in which Dade  Behring communicated to her the 15 day deadline  was clumsy and potentially confusing; but she  does not argue that she didn't understand, well  before the 15 day period of required notice began  to run, that she had to get the medical  documentation to Dade Behring by January 12 in  order to be eligible for family leave.


9
Affirmed.

