Proportion.

"Shredding and slicing, dividing and subdividing, the clocks of Harley Street nibbled at the June day, counselled submission, upheld authority, and pointed out in chorus the supreme advantages of a sense of proportion, until the mound of time was so far diminished..." (Woolf 155).

Here is the direct line drawn between "proportion" and "time."  Septimus Smith, who is going insane, is told by his doctors that he lacks a sense of "proportion."  It is shown here that proportion also means time--the clocks are sounding the "advantages of proportion."  This proportion, this respect to time, keeps people on tracks, makes them aware of their lives and how they are passing, aware of every moment.  Clarissa is aware, but Septimus is not.