Sync is Lightning Fast
Reminders is available on your iPhone, iPad, Mac, and Apple Watch, as well as on iCloud.com, and everything syncs between devices really fast. You can actually watch changes made on your Mac appear on your iPhone almost instantaneously.
Further, notifications also sync up between devices very quickly. Dismiss a reminder notification on your Mac, and it will almost instantly vanish from your iPhone screen as well. Snooze a reminder on your iPhone, and it gets snoozed everywhere else too.
One of the best parts is also that since it’s all built into iCloud sync services, you don’t need to worry about opening the Reminders app on your devices to ensure everything is in sync. It’s not uncommon in other task management apps to get reminded on your iPhone of a task you’ve already marked completed on your Mac. This basically never happens with Apple’s Reminders app — once a reminder is marked done, it’s marked done everywhere within seconds.