As well as being Virginia Woolf's original title for what would become Mrs. Dalloway, The Hours refers to the theory of time put forward by the French philosopher Henri Bergson. In his classic work Time and Free Will, Bergson distinguished between clock time, the time by which most of us arrange and organize our lives, and psychological time, in which we experience our inner states. According to Bergson, this is the time by which people truly live their lives as humans.
It is through the latter definition of time that Cunningham is able to explore the inner lives of his characters, all of whom, to some extent, experience a conflict between their inner and outer selves, a conflict which is expressed, respectively, through psychological time and clock time. Psychological time is the medium through which significant memories are recalled and brought to mind, such as when Clarissa reflects on the days she spent with Richard when she was younger.
Psychological time also provides an escape from an often harsh and unforgiving everyday world, a world whose grinding, insistent rhythms are determined by the ticking of the clock. By reading Mrs. Dalloway—the writing of which provided Virginia Woolf with an escape from such a world—Laura is able to deepen and extend her experience way beyond those brief, unfulfilling moments of clock time which she encounters in her daily life.