If a collective agreement treats part-time and full-time employees equally in accordance with the prorata temporis principle when paying wages or other divisible benefits of value, this excludes discrimination due to part-time work. This was decided by the Tenth Senate in its judgment of September 24, 2008 ( 10 AZR 634/07 ).

The regulation for calculating the remuneration of part-time employees in Section 24 Para. 2 TVöD, according to which part-time employees, unless expressly stipulated otherwise in a collective agreement, receive the table remuneration and all other remuneration components to the extent that corresponds to the proportion of their individually agreed average working hours of the regular working hours of comparable full-time employees, means that part-time employees who are constantly Shift and alternating shift work is carried out in accordance with the collective agreement, which is not entitled to the collectively agreed shift and alternating shift allowance in full, as is the case with full-time employees, but only pro rata in the amount of the quota between the agreed and regular collectively agreed working hours.

Part-time work differs from full-time work only in terms of quantity, not quality. § 4 Abs. 1 Sentence 2 TzBfG prohibits a deviation from the prorata temporis principle to the detriment of the part-time employee when paying wages or granting other divisible benefits in kind, without there being an objective reason for this. Part-time work can therefore only be compensated quantitatively, but not qualitatively, differently than full-time work. In its judgment of September 24, 2008 (6 AZR 657/07), the Sixth Senate decided that the regulations on overtime pay in Section 34 Para. 1 subparagraph 1 sentence 3 and subparagraph. 2 BATO against Section 4 Para. 1 TzBfG are violated and are therefore ineffective insofar as holiday pay, benefits and capital-forming benefits are not taken into account. It is irrelevant that full-time employees who work overtime do not receive increased vacation pay, higher benefits or higher capital formation benefits.

Rather, what is relevant is whether the total remuneration of the part-time employee, who, due to his overtime, works the same working hours as a full-time employee, corresponds to the total remuneration of a full-time employee. Only with such a comparison can it be determined whether a part-time employee receives the same remuneration as a full-time employee for every hour worked. As a rule, a part-time employee is not treated worse than a comparable full-time employee if the part-time employee receives an advantage to compensate for the disadvantage incurred. However, only those services that have a factual connection can be taken into account. The exclusion of operational-related dismissals is not suitable for compensating for disadvantages in terms of remuneration.