To add a shared Google Calendar that someone else created to your own Google Calendar is easy.

Add a coworker's calendar

Some coworkers will choose to share their calendars with their contacts. If this is the case then you can go to your Google Calendar and left sidebar next to Other Calendars click the Plus sign and then click Subscribe to calendar. You will be prompted to enter an email address and if that person decided to share their calendar then their calendar will also appear in your calendar. You can, like all other calendars toggle it by clicking the colored square next to the name of the calendar.

Browse Interesting Calendars

Google has a number of other calendars that you can add to yours, such as various holidays for different religions or different countries. In addition to holidays here are a number of calendars for different sports and calendars of seasons for leagues around the world. There are other calendars such as the phases of the moon or a calendar of sunrise and sunset times for your default location. To add any of these calendars simply click the Plus next to Other calendars then select Browse Calendars of interest. Then find a calendar you like and click the check box next to ir. If you get tired of seeing them you can toggle them by clicking the colored square next to the calendar or for a more permanent fix you can unsubscribe much the same way that you subscribed in the first place.

Add by URL

For some online calendars, if you know the address of the calendar in the iCal format, you can add the calendar to your own. For instance, you can add the REMC1 Onsite calendar to your own by opening the calendar, copying the address and pasting it in in the Add by URL section.

Alternatively, if you have the calendar open already then you can click the +Google Calendar button in the lower right corner of the calendar and it will take you to your calendar and ask if you would like to add this calendar to your calendar.

Import calendar

If you have the ability to download a calendar in an iCal or CSV format then you can browse your computer for it and upload it. It will be displayed with your other calendars.

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