Week n. : A period of seven days, usually that reckoned from one Sabbath or Sunday to the next.

Example:
What Week should I start prenatal appointments?

Taxonomy
cycle, Akan, six-day, rest day, nights, Aztecs, Seven-day, xún, grouping, free encyclopedia, Soviet Union, Ancient Balts, 5 day week, 10 day, 01-21, Lithuanian calendar, The Maya, national holidays.

Defination from the web:
week known as the Pasaran cycle. ... holidays in the earlier 5 day week remained and did not fall on the state rest day. But as January, March, May, July, August, October and December have 31 days, the week after the state rest day of the ...