Syncing alerts and alarms between devices (iPhone/iMac etc) in the Apple-world are very straightforward. But what if you have an Android phone and would like to have your Calendar alerts/alarms on your Mac also flag up on your phone?
Stumbled across this by accident. Set your default Calendar to your gmail account. You still set up events etc inside Apple Calendar as normal but they get replicated in Google-world. Then when an alarm/alert is triggered, it is a hop-skip and a jump for your gmail calendar (synced to your Apple calendar by default) to send an alert to your Android phone.