A kind of observing philosopher of the domestic, Rybczynski (an architect by profession: The Most Beautiful House in the World, 1989, etc.) here takes a look at time, work, leisure, and recreation--and at that entirely man-made phenomenon, the weekend. What might seem obvious is hardly so in Rybczynski's hands. There ``never has been a human society that did not recognize the need for regular days off,'' he tells us, and from there delves into an entertaining history of that ancient ``man-made'' interval known as the week (``What does the week measure? Nothing''), from there into the more modern history of what we call the ``weekend'' (it was born in England, in the 19th century), and from there into the study of what ``leisure'' has been in ages gone by, and of what it seems to have become today. With immense learnedness but an equivalent lightness and grace, Rybczynski touches, among other things, on the history of drinking, gardening, marketing, of stamp collecting and the use of country houses (including Pliny the Elder's), even on the history of reading and, more recently, of TV watching (``a poor sort of leisure''). All may not be entirely well just now with our own uses and understanding of either recreation or leisure, Rybczynski hints, particularly as we try too hard, through them, to compensate for a decline in the meaningfulness of work--but even here he remains equable and guardedly optimistic. Forfeiting the stronger narrative pull of The Most Beautiful House in the World (where a house, after all, was dreamed of, planned, and built), Rybczynski nevertheless offers a companionable ramble along a winding pathway of cultural history in a quiet and thinking book, a kind of intellectual browse that's--well, perfect for a leisurely weekend's reading.