Seventh-day Adventists observe the sabbath from Friday evening to Saturday evening. In places where the sun does not appear or does not set for several months, such as northern Scandinavia, the tendency is to regard an arbitrary time such as 6 p.m. as "sunset". During the sabbath, Adventists avoid secular work and business, although medical relief and humanitarian work is accepted. Though there are cultural variations, most Adventists also avoid activities such as shopping, sport, and certain forms of entertainment. Adventists typically gather for church services on Saturday morning. Some also gather on Friday evening to welcome in the sabbath hours (sometimes called "vespers" or "opening Sabbath"), and some similarly gather at "closing Sabbath".