Twitter is gaining popularity day by day and there are various web and desktop applications based on Twitter API. TwitMessenger is a another free web application which can schedule your tweets, which means you can publish to Twitter at any scheduled time automatically. The scheduling can be done for one hour interval starting from 1 hour to maximum of 48 hours.
Scheduling the tweets is simple process, log in with your twitter credentials and add the tweet you want to schedule with the time. You can also delete your scheduled tweets any time if you do not want to update.
The service does not mention about the maximum number of tweets that can be scheduled using this tool. This service could be useful in situations where you are going to be away from the computer or offline for one or two days, but still want to update your followers about some specific tasks.