How to get default reminders back on calendar?

[AC Question]

I have a Samsung Galaxy Note 4 and rely quite heavily on the built in calendar app. I have it synced with my google calendar and had default reminder of 30 minutes plus email notification. I tried taking the email notification off all my events and ended up losing the majority of my saved events plus have to manually set a reminder time for every event now. Any ideas on how to get default reminders back on?