How do you organize your appointments, update your agenda, plan events, and keep on time with your iPhone and iPad? The built-in Calendar app, of course!

Calendar lets you can create and edit appointments, share agendas, invite friends and colleagues to events, get alerted, stay on track and — most importantly — on time! You can set up Calendar to work with Apple's iCloud, Google Calendar, Microsoft's Outlook, and even CalDav calendars from your own or your company's servers. What's more, thanks to Siri, you can add, review, and even change appointments quickly and easily, and with the power of your voice.

Since iOS has a unified calendar database, whatever you add or change in Calendar will also be reflected in any third-party calendars you have installed, and vice-versa. Yes, everything is unified and stays organized, regardless of where or how you prefer to use it.

How to set up Calendar on iPhone and iPad

Whether you use Apple's iCloud, Google's Gmail, Microsoft's Outlook or Exchange, or something else, it's easy to set up all your calendar accounts and have them sync to your iPhone or iPad. You can enable iCloud when you first set up your new iPhone or iPad, or enable any service at any time in Settings.

How to customize Calendar in iPhone and iPad

Apple's Calendar app for iPhone and iPad lets you schedule everything from your workday to your household chores. It also lets you keep everything organized by color coding your calendars, setting time zones, setting calendar types — including Chinese, Hebrew, and Islamic — and even customizing default alerts. All so you can have your calendar your way!

How to add and manage calendar events on iPhone and iPad

The Calendar app for iPhone and iPad provides a great way to keep track of all your appointments and events. While it's faster to use Siri to create basic events to add to your calendar, if you need more precise control, or if you want to edit existing event details, you can do it the old fashioned way: by tapping your way through all the options!

How to share calendar events on iPhone and iPad

Apple helps you stay organized by letting you publish calendars on its iCloud service, and then share them with other people. It's great for when you have to plan events, whether they're conferences for work, or family vacations. Best of all, it's built right into your Calendar app on iPhone and iPad!

How to use Calendar with Siri

Since Siri is meant to be your personal assistant, it only makes sense to have it schedule and manage your meetings and events on your iPhone or iPad. Asking Siri to create a calendar event only takes a few seconds and is much faster than creating them manually and entering all the data yourself. Whether you need Siri to schedule a meeting, tell you what's on the agenda for the day, or move an existing meeting to another time to make room for a conference call or a power nap, Siri will help make sure your schedule is set.