You can also use Pocket to set reminders.
To set a reminder, say Remind me in 20 minutes to turn off the oven or Remind me in 1 hour to turn off the oven. After the amount of time you specified has passed, Pocket will say turn off the oven every 10 seconds for 5 minutes. To turn off the reminder once it has gone off press any button on your device. You can also set a general reminder by saying remind me in 90 minutes and Pocket will make a ringing sound once 90 minutes has passed.
You can check which reminders you have previously set by saying list reminders, Pocket will then list out all your set reminders. If you wish to you can then select a reminder from this list to cancel it.
At this time it is not possible to mix hours and minutes in reminders, meaning that if you want to set a reminder for an hour and 30 minutes, you will instead have to set an alarm for 90 minutes. Similarly it is not currently possible to ask for half hours only full hours, if you need to set a reminder with fractions of an hour you will have to convert this time into minutes.