There are three time spheres mentioned by Tom during "The Glass Menagerie." The first occurs before the opening of the play and is explained by Tom in the prologue. The most important occurrence during this time was the disappearance of Tom's father, "a telephone man, who fell in love with long distances." The father's abandonment of the family left them destitute and forced Tom to eventually become the breadwinner of the family, a job he intensely dislikes. The second time sphere occurs when Tom recounts his family's experience with the gentleman caller. This is the only time Laura has a chance at normality but her chances are dashed when Jim, the gentleman caller, announces he is engaged. The third time sphere occurs five to ten years after Tom, himself, has left the family. He states, "Oh Laura, Laura. I tried to leave you behind me but I have been more faithful than I intended to be." In other words, Tom is still haunted by Laura's memory and his decision to abandon her in order to gain his own independence.
"The Glass Menagerie" was first staged in 1945.
Tom as the narrator clearly indicates the three time spheres:
1. In Sc.1 Tom the narrator remarks,"To begin with I turn back time. I reverse it to that quaint period the thirties....a dissolving economy." So to begin with, Tennessee Williams takes his audience to the past-the economic depression of the 30s.
2. In Sc.5 Tom the narrator again reminds the audience of the time: "Adventure and change were imminent in this year...In Spain there was Guernica." The specific historical incident of the present scene took place on 26th April 1937 when Nazi war planes bombed the Basque town of Guernica in Spain. So, the incidents from Sc.5 onwards take place after 1937 and just before the second world war breaks out.
3. Tom's future: In Sc.7 at the end of the play Tom addresses the audience and informs them what he did from 1937,when he left home to 1945 the beginning of the play: "I didn't go to the moon, I went much further-for time is the longest distance between two places."
Thus the plot structure of the play is circular-it begins in 1945, goes back to the 3os, and more specifically to 1937 and back to 1945.