The novel is set in London, on a mid-June day (a Wednesday) in 1923. There is no real plot, but simply a mosaic of reminiscences , considerations about past and present situations , impressions , a sort of plunge into the continuous fluidity of life, measured by the striking of the hours (the original title was, in fact, The Hours).
It opens at 10 o'clock on Wednesday morning with Clarissa Dalloway (51, married with a daughter) , Bond Street buying flowers for the party she is giving in the evening, and ends with the party itself. The entire action is centered on her, and it is around her , between the opening and closing of the book, that a host of people come and go, meet and part, linked to each other by their present or past ties with Clarissa , and are finally brought together by her evening party.
It is through all these people's minds that the action effectively develops, through their thoughts, their feelings and recollections, presented no longer in linear progression, but in an alternation of flashbacks and present actions.
At the beginning of the novel we only know that Mrs Dalloway is going out to buy flowers for the house, where she is giving a party after same weeks of bad influenza. We know something about her external appearance only through the impressions of a neighbor. But a simple event puts her mental activity in motion, revealing her hidden ideas about time , about life and her instinctive love of life.