voskresén’e, “resurrection” day. Nedél-ya, "not working" is used in some Russian dialects.
ponedél’nik, po means "after", so "Mon-day" is expressed as the "day after the non-working day".
vtórnik, "second working day after the non-working day".
sredá, "middle" of the week.
cetvérg, "fourth working day after the non-working day".
pjátnica, "fifth working day after the non-working day".
subbóta, "Sabbath" day.
The fact that Tuesday, Thursday, and Friday are spoken of as the second, fourth, and fifth days instead of third, fifth and sixth, shows that the week is thought of as beginning on Monday. This is a natural idea from the point of view of workers.
This interpretation is opposed to ecclesiastical and biblical usage. It is thus in marked contrast with the strong religious feeling expressed in the ordinary Russian name of “Resurrection” day for Sunday.