Hi All, I wanted to give bug #1635737  some publicity, since it could lead to unexpected results once merged. The bug started as a way to ensure that time changes were taken into account when calculating due dates for circulations. The end result, apart from fixing the bug, is an interesting new feature that might cause confusion if you're not expecting it.
In short, circulation durations will be dynamic and context sensitive. For example... In Evergreen today, a circulation duration of "1 month" always means 30 days (plus a few hours which are essentially ignored). With the new code, "1 month" will have a different length depending on when it's calculated. An item checked out Jan 5 will be due Feb. 5, after 31 days. An item checked out Feb. 5 will be due March 5, 28 days later. The length of the month does not matter. And... this will now be called the "28 days later" feature. To have a duration that's always 30 days, then a duration value of "30 days" will behave as expected (with the added benefit of correctly handling time changes). Since circulation durations in EG are typically based on days and not months (or years), I don't expect this change to have a huge impact. It's good to be aware of it, though. Thanks, -b  https://bugs.launchpad.net/evergreen/+bug/1635737