What Is Calendar Sync? And Why Does It Matter?

Discover why calendar sync is a powerful feature in your application and how you can integrate this functionality into your app using a calendar API.

What is Calendar Sync?

We live in an impatient era. No one – from your employees to your customers – wants to spend even a few seconds on an unnecessary task. And research shows employees waste up to 50 days a year doing menial, repetitive tasks. This makes finding ways to simplify clunky, manual processes imperative. 

Calendar sync is a highly effective way to eliminate some of these inefficiencies. Connecting disparate systems gives your teams valuable time back and allows employees to focus on more pressing priorities than toggling between different calendars. 

Let’s explore calendar sync in more detail and explain how you can integrate this powerful capability into your application simply and securely using a calendar API. 

What is calendar sync?

To understand the true power of calendar sync, let’s break down the term into two parts and look at its definition: 


You may think, “I know what a calendar is. It’s where I keep track of important dates, schedule meetings or appointments, and share with others so they know when I’m free and busy.” And you’d be correct! Our calendars help us keep track of our lives, from everyday occurrences to the most significant milestones. 

However, the hidden business value within calendars (particularly scheduling) might not be so obvious. Think about it: Every business interaction with prospects and customers begins with a connection. Whether providing a quote or sharing more information on a product or service, getting time on someone’s calendar is more than a transactional checkbox. It’s an opportunity, often the first, to make a great impression. 

Another overlooked yet important aspect of calendars is that, more often than not, we use more than one. We track all the recurring events in our lives across different calendar providers, such as Google Calendar, Office 365 Calendar, Outlook, and more. For businesses, this is huge because being truly customer-centric means meeting your users where they are – in this case, integrating with their service provider of choice. And each provider has systemic features that process data differently. 

This brings us to our second term: 

Synchronization (sync)

By its primary definition, synchronization is when two or more things operate simultaneously (e.g., synchronized swimming). The computing meaning is a bit more helpful for understanding calendar sync. It’s the action of causing a set of data or files to remain identical in more than one location.

Simply put, syncing your data ensures it’s the same no matter which platform or system you view it on — a single source of truth. 

So, why is data synchronization necessary? It boils down to the issues of consistency and data integrity. When an organization synchronizes information, there’s less room for error, miscommunication, and duplication. 

When looking at the sum of its parts, calendar sync is when you connect calendars between two or more sources so data remains accurate, consistent, and secure. 

The pros and cons of calendar sync 

There are many advantages to syncing your calendars in real time. A few examples include: 

  • Saving time by eliminating the need to manually update multiple websites every time you receive a booking 
  • Streamlining productivity by eliminating the need to context switch across applications
  • Having an accurate, up-to-date representation of users’ availability, resulting in more streamlined scheduling and increased productivity 
  • Managing reservations and cancellations for activities like booking a rental car or property more efficiently
  • Decreasing the risk of scheduling mishaps during critical moments in time like candidate interviews 
  • Improving client relations, relieving customers of common pitfalls such as double bookings and cancellation fees

Though the pros outweigh the cons, there are a few roadblocks that can arise when performing a calendar sync: 

  • Allocating developer hours and dollars to building connectivity into each calendar provider’s unique characteristics can be time-consuming and costly 
  • Running into inconsistent behavior across calendar API providers (e.g., using non-standard formats for calendar data) can introduce unexpected complications
  • Scaling your integrations from a single user to many requires a relatively large amount of custom code

However, depending on your integration method, you can avoid common pitfalls while reaping the benefits of calendar sync.

Do top calendar providers offer a way to integrate?

The short answer here is yes, for the most part. The not-so-straightforward answer is still yes, but there are some nuances you should consider before starting an integration project. 

Calendar sync between the same service provider, such as Office 365 and Microsoft Calendar, is reasonably straightforward. Microsoft offers functionality to enable calendar sync in a few easy clicks via its administrative settings menu. 

The process gets a little more tricky when integrating multiple calendars within your application. The calendar API ecosystem is complex, and many calendar APIs lack the critical features needed to build a fully supported calendar integration.  

The best way to sync calendars in your app

Building an integration for one service provider from scratch can take as long as 12 months for a team of four engineers. And when doing so at scale, that undertaking becomes even more time-consuming and challenging.

Moreover, developers must maintain those connections and ensure that every calendar provider’s software is backward compatible, which can be tedious. And if calendar providers introduce breaking changes – or changes in their APIs that require your developers to take additional action – this can significantly hinder functionality and productivity.

You have a couple of options: 

  1. Task your developers with building unique integrations with every individual calendar provider, or 
  2. Use a single calendar API and save months of developer time integrating across every major calendar provider plus ongoing maintenance

You can probably guess our preference. A calendar API can power your application with real-time, secure, and two-way calendar sync while extracting complex integrations across multiple calendar providers. That makes it quick and easy to integrate scheduling functionality without worrying about ongoing maintenance. 

Ready to get started?

At Nylas, we’re experts at scheduling integrations. The Nylas Calendar API removes the complexity of syncing with digital calendar service providers, enabling fast and secure scheduling functionality.

Want to learn more? See how ATS platform Fountain built a calendar sync with just one engineer using the Nylas Calendar API or connect with a Nylas platform specialist.

You May Also Like

A Small Guide to Virtual Calendars
13+ Best Calendar Apps
13+ Best Calendar Apps
Build an old-fashioned agenda using Decker (HyperCard) and Ruby

Subscribe for our updates

Please enter your email address and receive the latest updates.