One way to "set alarms" for your followers is to create a meeting on your calendar (e.g. Google Calendar, iCal Calendar, etc.) for the day/time that the campaign goes live.

You can easily invite the folks on your email lists to this event via Gmail or Outlook and they can accept the invite and add it to their personal calendar.

If you have a budget attached to running this crowdfunding campaign, direct mail (i.e. postcards) can nicely complement electronic reminders.