Filter calendar events

Sometimes, you may want to subscribe to a calendar but would like to filter out irrelevant events and improve their display. This tool offers a simple solution.

Step #1: choose your preferences

Before	After	Options
		Shorten events that overlap the next event Hide all-day events Hide private events Predict event duration based on summary Remove event duration from title Skip events containing this text: * * use ';' to specify multiple blacklisted phrases. Comparison is case-insensitive. Hide events shorter than: min. Hide events from those Todoist projects: * * Skips events that are connected to any of the given Todoist tasks (based on iCalendar Description field added by Todoist when exporting items to calendar) Shorten events longer than min. to min.

Step #2: Transform your calendar the same way

URL of your iCalendar:

Your new URL:

https://filter.calendar.taurit.pl/filter?calendarUrl=https%3A%2F%2Fcalendar.taurit.pl%2Fassets%2FDemo-2016-01-01.ics

FAQ

Is this service free?

You can use it for free. I created this tool for myself and I don't mind sharing it. I reserve the right to introduce breaking changes (although I didn't for few years) or shut down the service at any time.

How secure and private is it?

Calendars contain private data, and the service that acts like a proxy can technically process this data in any way, including malicious scenarios. If you don't want to entrust some 3rd party service with the sensitive stuff, it's fully understandable.

While this web application does not do anything else than it promises, you don't have to trust it and you can verify all it does. The source code is published on project's GitHub page. If you have Visual Studio 2022 Community Edition or newer, you can build a project yourself with just a few clicks. If you like to tinker, you can host your own trusted instance of this code in AWS.

Why some filtered calendars can't be imported into Google Calendar?

Google Calendar's implementation seems to have a restriction on the URL's length. See this StackOverflow answer for details.

If you cannot import your calendar, you might try shortening the URL.

When I encounter this problem, I normally write and deploy a simple Azure Function which redirects to a real (long) URL, but itself has an acceptably short URL.

using System.Net;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Primitives;

public static async Task<IActionResult> Run(HttpRequest req, ILogger log)
{
    // example. Change URL to point to your calendar.
    return new RedirectResult("https://filter.calendar.taurit.pl/filter?calendarUrl=https%3A%2F%2Foutlook.office365.com%2Fsomelonglink.ics&st=filterdetails", true);
}

Where can I send feedback, bug reports or feature requests?

I encourage you to share any feedback, because it shall help me decide if this proof-of-concept is worth turning into a small product with more features. If I don't get any feedback, it will just stay what it is, as it fulfills my needs.

You can share your feedback by:

Creating an Issue on project's GitHub page
Leaving a comment under a blog post where I announced the Calendar Filter tool