Calendar Sync Insights

Which calendar app keeps you most up to date?

Timetastic serves over a million calendar feeds every month. Every time Google, Apple or Microsoft re-checks one, we see it, so we can show how fast they really refresh the calendars you subscribe to.

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calendar feeds tracked right now
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calendar checks we've recorded
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calendar apps & versions seen

Apple Calendar refreshes about 3.4× faster than Microsoft Exchange

Across the calendars we see, Apple Calendar typically refreshes every 1.8 hrs, while Microsoft Exchange takes around 6.2 hrs.

Live, last 14 days

How the big three are refreshing right now

Average time between fetches, per hour. The dashed line is each app's typical pace.

Apple Calendar
Apple Calendar
iPhone, iPad & Mac
Typically updates every
Google Calendar
Google Calendar
Google's calendar importer
Typically updates every
Microsoft Exchange
Microsoft Exchange
Outlook on the web & Microsoft 365
Typically updates every

The league table

Sync speed, ranked

How often each calendar client actually re-fetches a subscribed feed. Shorter is fresher.

1
Apple Calendar Fastest
iPhone, iPad & Mac
1.8 hrs
2,769 feeds
2
Microsoft Outlook
Desktop app for Windows
2.5 hrs
2,423 feeds
3
Google Calendar
Google's calendar importer
5.2 hrs
3,676 feeds
4
Microsoft Exchange
Outlook on the web & Microsoft 365
6.2 hrs
3,736 feeds

The long tail

It's not just the big three

Plenty of other apps quietly subscribe to these feeds, from calendar power-tools to job schedulers and even a family calendar screen on the kitchen wall. Here's a few we spotted.

Open-Xchange
OX App Suite email & calendar
44 min between checks
Thunderbird
Mozilla's email & calendar client
60 min between checks
BusyCal
Power-user calendar for Mac
60 min between checks
Fantastical
Flexibits' calendar for Mac & iPhone
62 min between checks
Teamup
Shared group calendars
62 min between checks
Skylight
The family calendar display
64 min between checks
Nextcloud
Self-hosted cloud & groupware
65 min between checks
HEY Calendar
37signals' take on the calendar
65 min between checks
Fastmail
Privacy-first email & calendar
73 min between checks
Morgen
Cross-platform calendar app
73 min between checks
ServiceM8
Job management for trades & field services
75 min between checks
Workamajig Most patient
Project management for agencies
12.6 hrs between checks

Most of the long tail keeps pace with the big names, re-checking roughly every hour. The most relaxed we see is Workamajig, which catches up about every 12.6 hrs.

What people share

The calendars teams subscribe to

Of the feeds we serve, whole-organisation calendars are the most popular.

Full Organisation
43.8%
My Calendar
29.3%
My Department
17.5%
My Favourites
6.4%
My Team
3%

How we know this

Timetastic lets people subscribe to their team's time-off as a calendar feed. Calendar apps (Google, Apple, Microsoft and others) re-fetch those feeds on their own schedule, and we record the moment each fetch happens.

The gap between two fetches is how long your calendar could be out of date. We take the median gap per app over the last 30 days, so a few stragglers don't skew the picture. We see a large slice of real-world traffic, but not all of it, so treat this as a very good guide, not gospel.

Anonymised & aggregated

We only count when calendar apps fetch feeds. We never look at who you are, who's in your calendar, or what any event says. No personal data or calendar content is read, stored, or shown here. Everything on this page is an aggregate.

Made by the team behind Timetastic

Timetastic is the simple way for teams to book and track time off, and it's what powers the calendar feeds behind this dashboard. Give your team a calendar that's always up to date.

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