Agenda At Once Free PIM - Agenda At Once Free PIM is complete, simple and powerful PIM freeware - to-do list software with schedule planner, contact management and notes.
Microsoft Outlook Calendar - Calendar is a time-management web application by Microsoft.
Notezilla - Colorful & powerful sticky notes app for Windows & Phones.
Calendar by Designs.ai - A complete calendar of all social media holidays.
EssentialPIM - EssentialPIM is a free Personal Information Manager that keeps up with the times and lets you manage appointments, tasks, notes, contacts, password entries and email messages across multiple devices and cloud applications.
Google Calendar - Spend less time managing your day & more time enjoying it