With the two remaining issues in the issue queue being fixed, I think Duration is sufficiently bug-free and nice enough for a stable release.
These two have been fixed since 6.x-1.0-rc2:
The API seems to work pretty nicely so far, which means this is mainly a bug fix release for a few edge cases.
Nevertheless, the API has been changed from uppercase function names to lowercase ones (with Views as role model) so any modules depending on the Duration API module will need to be adapted too, or they'll break. But hey, I haven't been at 1.0 still, so this can be expected.
Initial release! With a reasonable amount of features, already.
The API is great, and the CCK field is perfectly usable as is (coming with a few options and three different formatters).
The only thing that I feel is missing for a 1.0 release is a select widget for the CCK field... but if you just want to input your durations, tadah, go for it.
