As origi- nally enacted, Title VII did not spell out what it meant by discrimina- tion “because of ... religion.” Subsequent regulations issued by the EEOC obligated employers “to make reasonable accommodations to the religious needs of employees” whenever doing so would not create “undue hardship on the conduct of the employer’s business.” 29 CFR §1605.1 (1968).
quoted sentence: “To require TWA to bear more than a de minimis cost in order to give Hardison Saturdays off is an undue hardship.” Alt- hough many lower courts later viewed this line as the authoritative interpretation of the statutory term “undue hardship,” the context ren- ders that reading doubtful.
It noted that Title VII expressly provides special protection for “‘bona fide seniority ... sys- tem[s],’” id., at 81–82 (quoting 42 U. S. C. §2000e–2(h)), and it cited precedent reading the statute “‘to make clear that —————— ordinary meaning of “undue hardship” and “more than ... de minimis” led some to interpret the decision to rest on Establishment Clause con- cerns.
The Government agrees, noting that “‘undue hard- ship means something greater than hardship.’ ” Brief for United States 30; see id., at 39 (arguing that “accommoda- tions should be assessed while ‘keep[ing] in mind both words in the key phrase of the actual statutory text: “un- due” and “hardship”’” (quoting Adeyeye v. Heartland Sweet- eners, LLC, 721 F. 3d 444, 456 (CA7 2013)).
What matters more than a favored synonym for “undue hardship” (which is the actual text) is that courts must ap- ply the test in a manner that takes into account all relevant factors in the case at hand, including the particular accom- modations at issue and their practical impact in light of the nature, “size and operating cost of [an] employer.” Brief for United States 40 (internal quotation marks omitted).