Android & iOS: Tap on the task you want to set the reminder for. Underneath, you'll find . Tap it, and then you will be able to set a reminder for a specific date and time, or a daily/weekly/monthly reminder. Web, Mac, Chrome: Click on a task then click on Reminders. From there you can set a date, a time, and an alarm for your task by clicking on the date and time to the left of the reminder icon . When finished click the 'back' button.