1. has multiple views (i.e. daily/monthly, cross project) 2. has a feature for dates/deadlines 3. has a low-cost or free version
https://en.m.wikipedia.org/wiki/Comparison_of_issue-tracking...
https://en.m.wikipedia.org/wiki/Issue_tracking_system
https://www.redmine.org/projects/redmine/wiki/RedmineCalenda...