Certainly this modernist classic opens itself up to a multiplicity of different interpretations. However, one of the meanings that stands out to me is the approach of Alfred Prufrock to time, and the way that time is viewed with fear, trepidation and how this relates to indecision. Centrally, this poem concerns the speaker's fear of committing to a woman and how this will in turn ensnare him in the monotony of social conventions that make up life. Time is shown to be something that is elusive for him and resulting in his premature aging. Note how time is viewed in the third stanza:
There will be time, there will be time
To prepare a face to meet the faces that you meet;
There will be time to murder and create,
A time for all the works and days of hands
That life and drop a question on your plate;
Time for you and time for me,
And time yet for a hundred indecisions,
And for a hundred visions and revisions,
Before the taking of toast and tea.
Note the emphasis on how the speaker is trying to convince himself that "there will be time," shown by the repetition of this phrase. He is trying to convince himself that he doesn't have to commit yet, however at the same time he recognises that time is not infinite, and if he does not commit and make a decision against the "hundred indecisions" that are still open to him, he risks remaining lonely and old forever.
This perhaps explains the somewhat whistful and bleak tone regarding time, and life and how it slips away from us. The indecision of J. Alfred Prufrock is shown to be reflected in the tone of bleak disillusionment with life and society which the speaker seems to be both drawn to out of fear but also to despise.