From Social Patterns
A user needs to know when an event is happening.
- Use this pattern to alert others where an event is happening.
- Use this pattern to encourage sending reminders to a mobile device or email account.
When creating an event, allow the user to set reminders or alerts about those events.
If the event creator is inviting attendees, set the reminder to automatically send to the attendees.
Give the user the ability to select from a preset list of reminder times. For instance, Yahoo! Calendar offers to send reminders from 14 days before the event all the way to 5 minutes before the event while Google calendar allows you to specify an exact number and then qualifies it with minutes, hours, days, weeks, months etc.
Reminders should be able to be sent to an email address, to mobile devices or added to a social networking profile.
Consider allowing 2 sets of reminders to be set, for example 14 days and 5 days before the event.
For public events, allow people to set their own reminders.
Allowing users to set reminders is a standard feature of calendar tool and people expect it. The more useful the tool, the more likely people will continue to use it. People often schedule events far in advance and may for get them if a reminder is not sent. This tool allows event creators an easy way to send reminders without having to email everyone individually.