How to create a calendar event but keep my external calendar default alert times? I haven't been able to find an option to not override my external calendar (Google Calendar) default alert times and scheme.

I always have one email alert 1 day before and one normal reminder like couple hours before.

iCal and iOS calendar used to respect those default alert times up until iOS 10 / Sierra. But now I keep forgetting about going to places because I need a reminder the day before, like before sleeping so I plan my day correctly (wake up hours, etc).

The 1h reminder or time to leave reminders are great, but I really would like to be reminded the day before and like by email, because it's stays stacked in my inbox.

It's been such a pain that now I downloaded Google Calendar in my iPhone and I'm not using apple calendar anymore (but I wanted to be using it).

Does anyone have a tip on how could I fix that? It worked fine before. Thanks!
I had the same problem. I use Calendar all the time for email alerts and this has become very tedious. 

Here's a workaround:

Make a Calendar entry as a template: 

Create a generic email alert for one day ahead. Use a title you will remember like "one day alert," or maybe "1D" for a short name.

Use the template for a new Calendar entry:


If it's not immediately visible, make a same-date copy of the alert (I use option-click-drag). 
Retitle as desired &amp; add any needed details. 
Change the date (the date the template resides in) to the date you want. Doing this last will avoid an additional email alert.


Hope that helps.

Ps. You have to do this for each different lead-time you want for an alert. I nearly always use one or two days, so I created a template for each. I also made one that does both a one day and a two day alert.