The UI for setting dates and milestones could be improved. It displays the calendar at the top and the ‘Set as milestone’ checkbox below.
People typically work from the top down and so the invitation is to select the date, then check the milestone checkbox below, however, doing so overwrites any selected date with the current date as the milestone. Either the date selected should be used for the milestone date or the milstone checkbox should be above the calendar so that you select to create a milestone, then select the date.
Currently setting a date just have have it overwritten is annoying and this could be a simple UI improvement