Hourly reminders

Thanks for the screen shot. That helps. It looks like you are setting up a reminder that does not include a time. Once you enter a time, you should see ah hourly option. Please let us know if this helps.

Another factor to consider is what account is the reminder synced to. I can set up an hourly reminder if it's synced to my iCloud account. However, if it's synced to my Exchange account, that's not an option.

You can get general information on reminders here:

Use Reminders on your iPhone, iPad, or iPod touch - Apple Support

If this is not helpful, then please provide more information.

Glad it helped.