spatie/period – complex period comparisons in PHP

spatie/period is a PHP library that provides complex period comparisons.  It implements a variety of methods for calculating gaps, boundaries, overlaps, and other operations on multiple dates.

RRULE will make you hate calendars


Calendars are not the simplest applications by far.  There are many different features, lots of different implementations, multitude of standards (just a few being RFC 2445, which was obsoleted by RFC 5545, which was updated by RFC 5546, RFC 6868, RFC 7529, RFC 7953, RFC 7986) , and plenty of other complexities.

One area in particular, which is cryptic and annoying is RRULE, or recurrence rule.  You know, those events that don’t just happen once, but repeat once in a while.  Starting with the most basic rules of repeating every day, and going into complete insanity of repeating every other Thursday, starting from next week and until the beginning of next year every other month, RRULEs can drive even the calmest of people completely insane.  Here’s a screenshot to give you an idea.

Here are a couple of tools that we found useful, when implementing and testing this functionality:

  • rrule.js – a JavaScript library for working with RRULEs.  See the demo here.
  • recurr – a PHP library for working with RRULEs.

Radicale – Free and Open-Source CalDAV and CardDAV Server


Radicale is a free and Open Source CalDAV and CardDAV server.  Here are some of the features:

  • Shares calendars through CalDAV, WebDAV and HTTP.
  • Shares contacts through CardDAV, WebDAV and HTTP.
  • Supports events, todos, journal entries and business cards.
  • Works out-of-the-box, no installation nor configuration required.
  • Can warn users on concurrent editing.
  • Can limit access by authentication.
  • Can secure connections.
  • Works with many CalDAV and CardDAV clients.

Here is a blog post that provides some instructions on how to set it up and synchronize contacts and calendars between multiple services and applications.

Important Announcement about SMS notifications in Google Calendar


Catching up with emails, I saw this email from the Google Calendar team:

Starting on June 27th, 2015, SMS notifications from Google Calendar will no longer be sent. SMS notifications launched before smartphones were available. Now, in a world with smartphones and notifications, you can get richer, more reliable experience on your mobile device, even offline.

Too bad I say.  SMS notifications is one of the features I use and love the most about the Google Calendar.  My smartphone is full of all kind notifications.  In this day and age, it seems, every up considers it it’s duty to add something to the notification bar.  I’ll never configure each one of those to have a different sound, vibration mode, or LED color.  I don’t really care about them no more.

The ONLY notification that I care about 24×7, since my sysadmin shift days, is the SMS.  An SMS wakes me up in the middle of the night.  An SMS draws my attention in the noisiest of places.  An SMS interrupts my meetings.  That’s the one and only instance notification that I respect.

And now, it’s disappearing from the Google Calendar…