Take your calendar everywhere you go. If you have an existing calendar account (or several), import them all into the Calendar app. If you don't have an account, no problem. Just enter your events in the offline calendar.
To open the calendar app, tap on the Calendar icon, you probably need to swipe one or more screens to the right:
To import a calendar, tap the menu icon (top left).
Tap the plus sign on the next panel.
A sliding panel will appear which will allow you to choose your calendar provider. Tap the type of calendar that you want to add, then follow the prompts to log in.
To find out what version of Firefox OS you have, see What is my Firefox OS version?
Once you've successfully followed the steps, you will see a list of available calendars. Tap the ones you choose to sync with Firefox OS.
Once you have chosen the calendars you wish to import, go ahead and click on the settings icon on the lower left hand corner:
This will bring up your account settings screen allowing you to, for example, choose the time increment at which your calendar(s) should be syncronized.
Once you have finalized your settings and clicked Done, your calendar entries will be added and visible.
To add a new calendar entry directly on the device, click the + icon, located top right.
On the event screen, go ahead and add all of the relevant information of your new event. There is also room to add any additional comments you might want to associate with the event.
Once you have completed all of the information for your event, go ahead and tap on the Save button, top right. This will then save your new entry and redirect you to the Calendar view.
Keep the Calendar app in sync with your calendar accounts.
You don't need to be on a computer to add appointments. Adding them directly from your Firefox OS device is easy: