ISI Web of Knowledge [public access in PubMed] and archived in the OhioLINK EJC:
Friedman, William J.(Department of Psychology, Oberlin College) and Steve M. J. Janssen. Aging and the speed of time. Acta Psychologica, Volume 134, issue 2 (June, 2010), p. 130-141.
Partial abstract: "A total of 1865 adults from two countries, ranging in age from 16 to 80, reported how fast time appears to pass over different spans of time... Respondents of all ages reported that time seems to pass quickly. In contrast to widely held beliefs, age differences in reports of the subjective speed of time were very small, except for the question about how fast the last 10years had passed."
The experience of rushing, having many things to do and missing deadlines, correlated strongly with the feeling that time was passing quickly. The authors compared that sensation with that of a musician who is unable to keep up with the tempo of a metronome. I know that feeling all too well - and suddenly another 20 minutes has flown by!