My Samsung s5 only syncs with my Outlook 2013 calendar one way (calendar to phone). Why has Android not addressed the two-way sync with the popular Outlook program? I am purchasing the Samsung s7 today and I hope the sync issue has been perfected.
Welcome to Android Central! One might also ask the same about iOS apps and services. It's probably a combination of inter-company refusal to cooperate (in order to retain market share), lack of open source code, and perhaps relatively waning interest in Outlook.
This is one of the many benefits of using a hosted MS Exchange service. Seamless integration across all devices with email, contacts, calendar, tasks, etc. I don't think about it anymore. It just works.