This app was mentioned in 13 comments, with an average of 1.00 upvote
Someone asked for something similar a bit 2 months ago. The answer they got was Alarm Calendar Plus I've not used it, just remember it, as at the time I was looking for an alarm replacement.
One way you can sort of do this is with alarm calendar plus, https://play.google.com/store/apps/details?id=com.moyou.acplus
And google calendar and business calendar. You set calendar entries for your wakeup, teeth etc. You use business calendar to turn those into templates, so that they can be copied into multiple dates. Finally, alarm calendar plus reads the entries and sets alarms.
You can probably also do it with Tasker.
Check this out: https://play.google.com/store/apps/details?id=com.moyou.acplus
I think it can read the reminders in a robot voice. I used to use it but found another app I like better (instead of calendar entries being alarms they are repeating reminders which works better for me).
Alarm Calendar Plus hasn't been updated in over a year, but it has been reliably waking me up based on my calendar events. It's not the prettiest or easiest to understand, but it works.
I use Alarm Calendar Plus for my alarm clock. It doesn't do exactly what you're asking for, but it syncs with Google calendar to set alarms based on calendar entries. I work a rotating schedule, so the days I need to wake up for work change each week.
I don't know if this exists but it sounds cool.
I use Alarm Calendar Plus for this. It's a bit of work to set up but you can make it watch a Google calendar and it will create alarms for the events in it. It is highly configurable (e.g. I have one calendar where every event has an alarm at the time of the event but my main calendar only results in an alarm if the event has "alarm" in the title and it has the alarm go off an hour before the event).
How does this help you?
There are widgets and notifications to show "next alarm" which is basically like your next countdown.
Check it out: https://play.google.com/store/apps/details?id=com.moyou.acplus
I was missing meetings because google calendars alarms was so easy to ignore. This really shakes my leg when I need to get to a meeting.
Alarm Calendar Plus. You're welcome. https://play.google.com/store/apps/details?id=com.moyou.acplus
I used Calendar Alarm Plus for years to create alarms based on my calendar events. It might solve your problem.
I use Alarm Calendar Plus. It sets an alarm based on my calendar events. Not the prettiest app, but it has never failed me.