Why do we publish manuscript submission and accepted dates?

Recently Alex Bond, an ecologist at the University of Saskatchewan (his homepage and his blog) put out a question via Twitter:

Question for the masses: what's the reason journals put received, revised, accepted dates on papers? To show review times? Other?
— Lab and Field (@thelabandfield) May 26, 2013

The Canadian Field-Naturalist publishes the date when we first received a manuscript and when it was accepted.  We include this info at the bottom of all of our Articles and Notes (see pic below).

We do this for three reasons.

1. For us.  We want to monitor how long manuscripts take in the review and editing process.  Publishing those dates on articles is a sure way to keep the info handy so we don't lose it.  Once we move to our online manuscript management system we will have more detailed info available for ourselves (e.g., dates of each review, dates of editors' correspondence, etc.).  These data allow us to evaluate the performance of practices and personnel to see what is related to turnaround times.
2. For potential authors.  According to a survey of ecologists by Aarssen et al. (2008), the likelihood of a rapid decision was an important factor in choice of journal for submission for 72% of ecologist.  This could be why some of the mega-publishers are tricky in their turnaround time statistics; they "reject" manuscripts instead of calling it "revise", and count the submission of the revised version as a new submission.  This makes it look like the turnaround times are shorter than they actually are.  It's sketchy, and authors are blowing the whistle on this deception.
3. For researchers.  Kareiva et al. (2002) and O'Donnell et al. (2010) analyzed manuscript turnaround times for a variety of journals, and found conservation journals were kinda slow, but getting faster over the past decade.  Considering conservation journals pride ourselves in publishing research relevant to policy makers, being slow could delay conservation policy action.  Kareiva et al.'s 2002 paper may have even been a "wake up call" for conservation journals, which O'Donnell et al. (2010) found subsequently reduced their turnaround times.  Other researchers are interested in the relationship between turnaround times and things like journal Impact Factor (e.g., Pautasso & Schäfer, 2010).  We're guilty of being slow, but over the past year our turnaround times have shortened considerably (I don't have the stats right now, but we've shaved many months off).  This is the result of great effort from our Editor-in-Chief, Associate Editors, reviewers, and of course authors.  Switching to our online manuscript management system should further reduce turnaround times, according to findings from other journals switching to such manuscript systems (Ware, 2005).

It's not just us who feels journals should publish these dates.  The Committee on Publication Ethics includes the publication of articles' dates of submission and acceptance as best practices for journal editors (pdf of their guidelines for editors).  Publishing manuscript dates is the right thing to do, and we'll continue to do so.

REFERENCES:
Aarssen, L. W., T. Tregenza, A. E. Budden, C. J. Lortie, J. Koricheva, and R. Leimu. 2008. Bang for your buck: rejection rates and impact factors in ecological journals. Open Ecology Journal 1:14-19.

Kareiva, P., M. Marvier, S. West, and J. Hornisher. 2002. Slow-moving journals hinder conservation efforts. Nature 420:15.

O'Donnell, R. P., S. R. Supp, and S. M. Cobbold. 2010. Hindrance of conservation biology by delays in the submission of manuscripts. Conservation Biology 24:615-620.

Pautasso, M. and H. Schäfer. 2010. Peer review delay and selectivity in ecological journals. Scientometrics 84:307-315.

Ware, M. 2005. Online submission and peer-review systems. Learned Publishing 18:245-250.