Понедельник это первый день после недели. Monday is the first day after the last week.
Вторник это второй день недели. Tuesday is the second day of the week.
Среда это середина рабочей недели. Wednesday is a middle of the work week.
Четверг это четвёртый день недели. Thirsday is the fourth day of the week
Пятница. This day is named in honor of an old Slavis goddess with a name Pyatnitsa, but, I think, it will be easier to remember the name of this day as пятница это пятый день недели. Friday is the fifth day of a week.
Christian religion influenced names of the last two days
Суббота comes from Hebrew "sabbath".
Воскресенье это день, когда воскрес Иисус. Sunday is a day when Jesus was resurrected.
Didn't неделя originally mean Sunday (something like "do-nothing, day of rest")? So that понедельник is really the day after Sunday rather than the day after the week before? Not that it's easier to remember that way :-)
Edit: I'm also curious about the source for an old Slavic goddess named Pyatnitsa. Russian Wikipedia (I know, Wikipedia) and Wiktionary both state that it's simply derived from пять with no mention of a goddess Пятница.
As far as I know yes, "неделя" meant Sunday, but it was called this way in times of Ancient Rus, so I thought this explanation will confuse people. And I decided to write this as the first day after the last week.
About Pyatnitsa (in Russian)
Thanks for the links. I'd read about the Orthodox saint but didn't know the connection to Slavic mythology. I may have missed it in the links but neither of them, as far as I could tell, claims that the name was taken from the goddess rather than the other way around? One of your links and Wikipedia both speak of her as being a personification of the fifth day of the week, or my Russian is seriously letting me down.
As far as I know yes, she is a personification of the fifth day of the week. Because, if the name of Friday comes (in Russian) from a number five, then it can be called, for example, Пятник or Пятак, but it is not called this way.
The Sabbath is the day of rest, which is the 7th day of the week (a.k.a Saturday).
"И совершил Бог к седьмому дню дела Свои, которые Он делал, и почил в день седьмый от всех дел Своих, которые делал. И благословил Бог седьмой день, и освятил его, ибо в оный почил от всех дел Своих, которые Бог творил и созидал." Бытие 2:2-3 SYNO