Desktop-Reminder - Desktop-Reminder is a freeware task planner for Windows to manage your tasks and other to-dos’ in really easy way.
Lightning Calendar - Organize your life — it’s about time!
Date Reminder - Date Reminder reminds you of recurring or nonrecurring events, like birthdays, bills to pay...
GMinder - GMinder is an open source Windows System Tray app that pops up to remind you about Google Calendar events.
024h Lucky Reminder - 024h Lucky Reminder is a reminder software for home and office.
Calendar Lock PEA - Calendar Lock PEA is an encrypted desktop calendar with a day, week and month view. The shown calendars are never stored unencrypted on your disk, but exist only in the RAM. Platform-independent, Open Source, no installation or registration required.