In Book I, Chapter 2, we introduce you to the concept of open source software and discuss the WordPress development community being primarily volunteer developers who donate their time and talents to the WordPress platform. The development of new WordPress releases is a collaborative effort, sometimes requiring contributions from more than 300 developers.
The public schedule for WordPress updates is, roughly, one new release every 120 days. As a user, you can expect a new release of the WordPress software about four times per year. We can attest that the WordPress development team sticks to that schedule closely, with exceptions only here and there. When they make exceptions to the 120-day rule, they usually make a public announcement about it so that users know what to expect and when to expect it.
Mostly, interruptions to the 120-day schedule occur because the development of WordPress is primarily on a volunteer basis. A few developers — employees of Automattic, the company behind WordPress.com — are paid to develop for WordPress, but most developers are volunteers. Therefore, the progress of WordPress development depends on the developers' schedules.
I'm confident in telling you that you can expect to update your WordPress installation at least three, if not four, times per year.
Don't be discouraged or ...