If you ever want to create a reminder with an alert time, it's easy to do, and it's similar to Calendar's Quick Entry feature.
Just type something like "Dinner with grandpa at 6pm", and you will get a reminder with an alert at 6pm today. You can even specify a date, or use relative dates like today, tomorrow, etc.
[kirkmc adds: This makes sense, and it's good to remind people of it.]
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