I have been annoyed by this long enough to complain about it here. Just look at this page: https://admin.fedoraproject.org/updates/F10/ Why do I need to see pages and pages of very old but undated packages before I finally get to see what is really recent? How unprofessional! It is either web front-end should be more intelligent about sorting, or bodhi should be strict about the time data, or default to year 1969 to discipline the maintainers.
This was caused by some bug during the updates push process that caused a batch or two of updates to go out without the date_released field. This has happened in the past, and I've written code to to fix it. I'll look into the cause of the problem and see if I can clean up this mess. Thanks for the report.
I fixed the updates with the missing timestamps. It should hopefully look less "unprofessional".
"Stable" and "Pending" look beautiful now. I wonder why "Testing" is not fixed. Thanks!
Someone submitted a patch recently that shows pending updates that are on their way to testing in the main Testing list, which is why the top updates do not have a date pushed timestamp.