Calendar App Opening in Pocket

[anon(238680)]

For the 6th or 7th time when my phone is in my shirt pocket I see a full screen almost empty page with a "Tap to Set" in the middle. Phone is not unlocked, Smart Lock is not set and I touched nothing on the phone. Tapping the screen takes me to unlock, then a set page comes up from the calendar app. No idea where this is coming from but it's really annoying. Not sure if it's the Samsung calendar or the Google calendar as they both look pretty much the same.