Countdown notification to next event

[iFortWorth]

So I'm confused. Apparently some app, sometimes, places a countdown timer to an impending event. I can't figure out the rhyme or reason to it. But kinda like it. It's usually within an hour of said event.

It's only done it a couple of times and I can't seem to consciously replicate it. Any idea what app that may be?

I do have Outlook installed as well as Google Calendar and Samsung Calendar.

My device is the Note 9. And the app I primarily use for creating events is Google Calendar.

I know this is kinda vague but hoping someone has seen this before.

Thanks