with whom BRUNETTI, KOZINSKI, and FERNANDEZ, Circuit Judges, join, dissenting in part:
I agree with the majority on the law, but disagree on the application of law to fact that results in a remand.
The majority holds that a bona fide seniority system does not relieve an employer of the duty to make reasonable accommodation, if that accommodation can be accomplished consistently with the seniority system and with no more than de minimis cost. I agree that that is a correct reading of Trans World Airlines, Inc. v. Hardison, 432 U.S. 63, 97 S.Ct. 2264, 53 L.Ed.2d 113 (1977). The majority holds that because the seniority system in the case at bar prohibited employees from trading shifts on more than an emergency basis, requiring permanent shift trading to accommodate appellant’s religious beliefs would cause the City an undue hardship. That too is correct.
But the majority errs, in my view, in holding that there is a genuine issue of fact about whether “splitting shifts” to accommodate appellant’s religious beliefs would be an undue hardship for the City. What the majority means by “split shifts” is split days off, so that instead of a two day weekend, an employee would have two one-day breaks (e.g., work swing shifts, take Friday off, work Saturday, Sunday, Monday, take Tuesday off, work Wednesday and Thursday). Appellant suggested this so that she could take her Sabbath off. *1057I believe the record establishes that this accommodation would cause more than de minimis cost to the City, and thus, is not required. The reason the majority errs, in my view, is that although the opinion correctly states the basic holding of Hardi-son, the majority gives too little weight to the preclusive effect a bona fide seniority system has on religious discrimination claims, and erroneously converts a de min-imis cost standard into something more demanding.
Lieutenant Dwight Dimit testified that he is the person who actually does the shift assignments. The majority says .that there is a genuine issue of fact because Lieutenant Dimit’s supervisor, Chief Deputy William Callahan, did not know whether or not there would be hardships for Dimit in scheduling split shifts. But Chief Deputy Callahan’s lack of knowledge about operational details does not contradict anything Lieutenant Dimit said and does not create a genuine issue of fact. In any office, there will be some things that the boss does not know about the operational details of the work performed by those the boss supervises. Shift assignment was Dimit’s job, not Callahan’s, so Dimit, not Callahan, knew how much trouble split shifts would entail.
Lieutenant Dimit testified that “I do the schedule.” The way he did it was that twice a year, he hung a memorandum on a bulletin board, with a list of all deputies’ names in order of seniority. In seniority order, they bid for shifts, such as swing shift with Sunday and Monday off. Anyone on a day shift had to take a swing shift or graveyard shift for the next six months. The memorandum lists each shift, in the form
SWING
51-Tue/W edS3-Thr/Fri
52-Sun/MonS4-Fri/Sat
On the bottom part of the page, the fourteen deputies are listed in order of seniority. They fill in blanks next to their name, in seniority order, in the form,
1. FARRELL S2
2. JONES D2
3. JANAS R1
4. KELLER TR
5. STEEL G1
[Remaining nine deputies omitted.]
This election procedure generates a chart for each month of the six month period, with the fourteen deputies listed down the left axis, and each day of each month along the top axis, with a code filled into each box for day, swing graveyard, or time off.
The jail had never split days off before, so when Balint’s lawyer asked Dimit about what that would entail, he was necessarily asking about a hypothetical circumstance with which the jail had no experience. The fact that split days off had never been done, and that there was a long established system of two consecutive days off as part of the assignment system, means that splitting days off as Balint proposed would conflict with the established seniority system. When Balint suggested split days off to Dimit, he bucked her suggestion up to his supervisor, Chief Deputy Callahan. Dimit testified that the occasional shift swap had become “a logistic nightmare,” so they were discouraged. If Balint were allowed to split her weekends, then “we could run into problems with the contract” because of “[ejxcess of 40 hours worked in a week.” Under the terms of the City’s agreement with the deputies, Lieutenant Dimit expected to run into problems with overtime. Figuring the start and end of the seven-day workweek for overtime computation purposes would be problematic, Lieutenant Dimit thought, if the two days off were nonconsecutive.
Balint’s unavailability for Friday evening to Saturday evening posed an especially difficult problem because Friday night is a busy law enforcement night. Because they do not have to go to work the next morning, many people do something a little different on the nights before their days off. Some people, who have always provided a disproportionate share of police and jailer’s work, go out, get drunk, and get in fights. See, e.g., United *1058States v. Cunningham, 54 F.3d 295, 302 (7th Cir.1995) (referring to “a routine Friday night bar fight” and saying “fights among young men on Friday nights in places like Cedar Lake, Indiana — following too many beers — are not uncommon. Retaliation for some actual or perceived insult is often the cause of these ‘head thumpings.’ ”). Deputy Chief Callahan wrote in his affidavit that “more arrests and bookings occur in Detention on Friday and Saturday evenings ... a 25% higher rate of bookings.” Deputy Chief Callahan wrote that the “dysfunctional” arrests those nights caused many deputies to “prefer that their days off fall on Friday and Saturday.” But because of the additional arrest rate, Lieutenant Dimit testified that Friday and Saturday nights were the only time he needed three deputies, instead of two, on the graveyard shift.
Chief Deputy Callahan submitted an affidavit that it would cost the department $6,614 per year to cover for Balint taking her Sabbath off. His calculation is based on the assumption that she would have to be replaced by a senior person for eight hours every week, who would then get overtime. In addition to the financial burden, he was concerned about “increased possibility of officer burn-out and potential increased risk of injury due to the long continuous stretch of working hours.”
Possibly things would not turn out to be as bad as Lieutenant Dimit and Chief Deputy Callahan feared if they accommodated Ms. Balint, but their evidence is uncontra-dicted and establishes more than a de min-imis cost, so that should be the end of the case. Even if accommodation were possible, it is plain and uncontroverted that the department would, at the least, have to: (1) survey the deputies to see whether any of them wanted to split their days off; (2) prepare new charts for each month remaining in the six-month period if anyone did; (3) analyze whether the new arrangement would create any legal problems under the collective bargaining agreement or the wage and hour laws; (4) pay any overtime required; (5) deal with any unforeseeable problems that arise from an entirely new way to allocate work. That generates a great deal of trouble, risk and possible expense. The six month shift arrangement would be disrupted. An office might voluntarily go to all this trouble to accommodate a long-time well-regarded employee, but creating a new system of allocating shifts and redoing everything in accord with it if someone volunteered to split weekends is a lot to impose on an office for someone who has never worked there. Considering that staffing was already half again as heavy for the Friday and Saturday night shifts, and considering that senior deputies tried to avoid working Friday and Saturday nights because of the large number of what Chief Deputy Callahan called “dysfunctional” bookings those nights, efforts to try to accommodate Bal-int were likely to be a waste of time. On this record, the majority errs by requiring the jail to make these burdensome efforts.
The reason the majority errs, I think, is underestimation of the force of a seniority system. The statute says that an employer may not “discriminate against” a person because of that person’s religion, and defines religion to include all aspects of practice. See 42 U.S.C. § 2000e(j). An employer is required to accommodate the worker “unless [the] employer demonstrates that he is unable to reasonably accommodate ... without undue hardship.” 42 U.S.C. § 2000e-2(a)(l), 2000e(j). But then Congress trumped this provision with a “notwithstanding” provision. The “notwithstanding” provision says that an employer can impose different terms of employment pursuant to a bona fide seniority system without violating the statute, so long as the seniority system is not the result of an intention to discriminate. Choosing which provision controls if there is a conflict is easy. Congress wrote that the seniority provision controls “[notwithstanding any other provision of this sub-chapter,” 42 U.S.C. § 2000e-2(h), which includes the religious accommodation language.
The facts in Trans World Airlines, Inc. v. Hardison, 432 U.S. 63, 97 S.Ct. 2264, 53 L.Ed.2d 113 (1977), are analogous in mate*1059rial respects to the facts in the case at bar. That case held that further efforts to accommodate were not required. The Court in that case discussed TWA’s efforts to accommodate, but it did not say that such efforts were necessary. TWA tried to work with the union on an accommodation, but the union had turned down TWA’s request for an exception to the seniority system for shift allocation in the collective bargaining agreement. See id. at 77-78, 97 S.Ct. 2264. During the Hardison litigation, the district court thought TWA’s efforts were sufficient, but the circuit court, which was reversed, did not. The circuit court erroneously opined that TWA ought to look into a shorter work week or a swap with other employees to cover Hardison’s Sabbath shift, very much as we have required further efforts in the case at bar.
The Court said that the emphasis of the statute was that “similarly situated employees are not to be treated differently solely because they differ with respect to race, color, religion, sex, or national origin.” Id. at 71, 97 S.Ct. 2264. The Court said that a seniority system is itself “a significant accommodation,” because “the seniority system represents a neutral way of minimizing the number of occasions when an employee must work on a day that he would prefer to have off.” Id. at 78, 97 S.Ct. 2264. The Court pointed out that if it allocated days off in accord with employees’ religious needs instead of using a neutral system, “it could have done so only at the expense of others who had strong, but perhaps nonreligious, reasons for not working on weekends.” Id. at 81, 97 S.Ct. 2264.
The Court explained that the accommodation language was found in the definitions section of the statute, but the seniority provision was in the operational language, stating what an employer could not do. The “unmistakable purpose” of the seniority language was to “make clear that the routine application of a bona fide seniority system would not be unlawful.” Id. at 82, 97 S.Ct. 2264. “Thus, absent a discriminatory purpose, the operation of a seniority system cannot be an unlawful employment practice even if the system has some discriminatory consequences.” Id.
This plain holding in Hardison means that even if a bona fide seniority system has the effect of “discriminating against” (in the special and limited sense of not making special accommodation for) an employee’s religious needs, that discrimination is legal. The Court went so far as to hold that the statutory term “undue hardship” was satisfied if.the employer were required to “bear more than a de minimis cost.” Id. at 84, 97 S.Ct. 2264. The Court explained that to impose more than a de minimis cost on the employer “would involve unequal treatment of employees on the basis of their religion,” as, for example, choosing which employees would enjoy the benefit of additional costs “on the basis of [their] religious beliefs.” Id. “In the absence of clear statutory language or legislative history to the contrary, we will not readily construe the statute to require an employer to discriminate against some employees in order to enable others to observe their Sabbath.” Id. at 85, 97 S.Ct. 2264.
One of America’s great achievements has been to make an individual’s religion irrelevant to how the law requires people and institutions to treat him. As Hardison points out, a religiously neutral seniority system for allocating the better shifts at a workplace is itself a means of accommodating religious preferences. It means that employees can accommodate their own religious needs to the extent that their seniority and others’ preferences permit, by choosing the shifts and days off they need to practice their religions. Hardison points out a significant concern if the law requires too much accommodation of religious preferences. Religious accommodation becomes religious discrimination, if some people are put in a better position than others because of their religion. I can think of few Establishment Clause issues that would matter more to people than whether the government makes'them work overtime or during a shift when they want to be home with *1060their families, because someone more religious, or with a different religion, wants to take the time off for religious purposes. Ordinary civility, as well as the definition of religion in the statute, compel de min-imis accommodation to people’s diverse religious needs. Religious toleration is not going to disappear if we construe the law to require more, but there is no reason to strain toleration by a construction that requires significantly more expense and trouble to be undertaken in the workplace for some people than others, on account of their religions. In this case, even if the jail could find someone to split their weekend into noncontiguous days off and work the undesirable weekend time Balint needed for her Sabbath, looking for that person would take a considerable amount of trouble and would conflict with the well-established neutral seniority system, and finding one would involve considerable administrative effort and potential overtime expense. As a matter of law, this accommodation would therefore be, as the district court held, “more than a de minimis cost,” so the employer did not have to bear it.