Google Calendar is a free time-management web application offered by Google. The Ajax-driven interface enables users to view, add, and drag-and-drop events from one date to another without reloading the page. It supports view modes such as weekly, monthly, and agenda. Google Calendar allows multiple calendars to be created and shown in the same view. Each can be shared, either read-only or with full edit control, and either with specified people or with everyone (public calendars).

Yahoo! Calendar is a Web-based calendar service from Yahoo!. It can read calendar feeds and events syndicated from sites that make use of the published Yahoo! calendar programming interfaces.

2018 - G Suite apps and Google Calendar are getting Gmail’s side panels
One of the best features of the new Gmail is its quick-access side panel with easy access to Google Calendar, Tasks, Keep and your Gmail extensions. Now, Google is bringing this same functionality to Google Calendar, Docs, Sheets, Slides and Drawings, too. In Google Calendar, you’ll be able to quickly access Keep and Tasks, while in the rest of the G Suite apps, you’ll get easy access to Calendar, Keep and Tasks. Paying G Suite subscribers on the rapid release schedule should get access now, with those on the slower release schedule getting access in two weeks.
2018 - Google Calendar gets an Out of Office mode
Google Calendar gets a new “Out of Office” feature along with setting customizable working hours. The working hours signal to others when you’re unavailable, and allows Google Calendar to automatically decline meetings on your behalf outside those hours. For starters, you’ll find there’s a new “Out of Office” calendar entry type you can select when you’re creating an event via Google Calendar on the web. For example, if you’re scheduling the dates of your vacation, you could mark that event as “Out of Office.” If others send you meeting invites during this period, Google Calendar will decline them without your involvement.
2018 - Google Calendar now lets you add a message when you change an event
Google Calendar gets a new useful feature. When you change or delete an event, a dialog box now pops up that allows you to attach a short message to the event to explain why you are making the change and what’s changing. On the event page in Google Calendar itself — and in the email that alerts your guests of the change — that message will then appear at the top of the event details section. The new dialog box appears automatically, so far more people will now explain their changes than before. This new feature is now rolling out to all G Suite users and should be available to everybody (no matter whether their admins have them on the rapid release or schedule release schedule) within the next three days. Thereby Google Calendar now provides better notofications than Yahoo Calendar
2017 - Google redesigned Calendar for web to win over CalenGoo
Google rolled out new updates for the web version of Google Calendar, finally giving PC users the sleek layout and intuitive controls offered on the mobile app version of the G Suite tool. The redesigned calendar layout will automatically adjusts to better fit the size of your screen. Most of the other features coming with the web redesign will be helpful for people using Calendar within wider organizations. The handiest of these will now allow you to check out multiple users' calendars side by side for a given day, in order to see how everyone's schedule lines up. Calendar Invites now allow to add formatting and hyperlinks directly into the description field, and G Suite administrators will be able to include more details about conference rooms within an organization. So we may assume that Google Calendar gets more business-ready in comparison to CalenGoo
2017 - Google Calendar improves integration with Microsoft Exchange
For companies that use both Google’s G Suite and it's Microsoft alternative - Exchange in parallel, the new Google Calendar update arrived. G Suite admins can now allow their users to see real-time free/busy information across the two systems. This means tools like Google Calendar’s Find a Time feature and Outlook’s Scheduling Assistant can now easily talk to each other, for example. Once an admin has enabled them, these new Calendar Interop features will be available on Google Calendar for Android, iOS and the web, as well as all Outlook 2010+ clients on desktop, mobile and web.
2017 - Alexa now works with G Suite calendar to strike back at CalenGoo
Amazon’s connected speakers and other Alexa-powered devices will now work with your G Suite calendar. Once enabled, users will be able to ask Alexa to give them an overview of their day or make changes and other additions to their calendar as needed, just by speaking. The change represents another step towards making Echo and other Alexa speakers more practical devices to have in the office, or for general business use. G Suite is not the first calendaring platform that Alexa supports. The company has offered Google Calendar integration since launch, and added support earlier this year for both Outlook Calendar (including Hotmail, MSN, and Live email accounts) as well as Office 365 Calendar, for those with Exchange Online mailboxes.
2016 - Google Calendar added reminders on the web to win over Fantastical
Last December Google added a to-do function called Reminders to the Google Calendar iOS and Android apps. Recently it became available in the web version. Reminders basically amp up Google Calendar’s to-do list, so you can not only create tasks in your Gmail inbox, Google Keep, or calendar, but see a reminder that shows up on top of your Google Calendar, haunting you until you finally pay that bill or call that person or do whatever it is that you keep putting off.
2015 - Google acquired mobile calendar app Timeful
Google has acquired the calendar app Timeful that is intended to reduce stress, increase productivity, and bring better life balance to all the people overwhelmed by everything that competes for their time. The app worked by initially learning the daily scheduling habits of its users, before using notifications to help prioritize certain tasks. If the user stated their intention to go to the gym three times a week for instance, the app would offer suggestions and reminders for scheduling those sessions in during a user’s free time. Google plans to apply Timeful’s technology “across products like Inbox, Calendar and beyond,” Product Management Director Alex Gawley said in a blog post.
2015 - Google Calendar is available on iPhone. MS Outlook should better react
Google launched the revamped calendar app for Android back in November, and now Google Calendar officially landed on the iPhone. iPhone users were always able to import Google calendars into the standard iPhone Calendar app, or other third-party apps, but now Google Calendar finally has an iOS app to call its own. It comes with new features, like Events from Gmail, which automatically transforms events from emails into Calendar events. There are also Assists, which is a kind of autocomplete, suggesting text from different sources to make filling out Calendar event forms much quicker. Lastly, it has a new scrollable format called Schedule View. This view is more intuitively designed for mobile.
2014 - New Google Calendar for Android allows to enter events automagically to defeate BusyCal
Google is rolling out a new Google Calendar app that works on Android Lollipop 5.0 and all Android 4.1 or newer devices. The new app includes three key updates that allow it to fill in the blanks and make suggestions for you, shortly after you start to type in your event. The new Schedule View will let you see a map of your event destination. It will also include photos, cityscapes and illustrations of the surrounding area. Another new feature - Assists - that basically guesses details to add to an event, based on your previous phone interactions. For example, if you run with a friend in the park every week, the new version of Google Calendar will suggest the place, time and person you always go with if you start to type “r-u-n.”