for time off: appellant does not ask for payment for time when he is not working. Moreover, we are not ready to hold that the school board has shown that there will be a greater than de minimis loss in efficiency. The Hardison Court held that using a supervisor or an employee from another area amounted to a greater than de minimis cost because it left other operations undermanned. The same problems may not arise under the substitute accommodation. One would suppose that the school system has the ability to find qualified substitutes. If appellant communicates with the substitute before and after the days he must miss, there may well be no appreciable loss in the quality of education, where the number of additional substitute days appears to be three. Cf. Turpén, 736 F.2d at 1028 & n. 6 (<HOLDING>). The school board also suggests that
holding that the district courts finding of no discrimination under title vii was not clearly erroneous because the finding was supported by the record holding that it was not clearly erroneous for the district court to find that a substitute accommodation caused undue hardship when there was no builtin system for substitution holding that district courts findings were not clearly erroneous where there was  sufficient evidence  that the defendants waiver of his rights was knowing and intelligent holding that it was not clearly erroneous for the district court to consider survey evidence even though the survey was imperfect holding that the district courts finding of no discrimination was not clearly erroneous because the finding was supported by the record