JavaScript.com VS Leap Second

• Comprehensive Learning Resource
  JavaScript.com offers a wide range of tutorials and guides that cater to both beginners and experienced developers, providing a good foundation in JavaScript.
• Interactive Content
  The site features interactive exercises and examples that help users practice and understand complex JavaScript concepts effectively.
• Community Support
  Being part of a broader developer community, it allows users to engage with other learners and experts, facilitating collaborative learning and problem-solving.
• Up-to-Date Information
  The website frequently updates its content to reflect the latest trends and changes in the JavaScript language and ecosystem.

Possible disadvantages

• Limited Advanced Content
  While the site covers basics well, it may not delve deeply into advanced JavaScript topics, which could be a limitation for experienced developers seeking in-depth knowledge.
• Website Navigation
  Some users might find the navigation and organization of content slightly confusing, making it harder to find specific information or topics quickly.
• Dependence on Internet Access
  As an online resource, constant internet access is required, which can be a limitation for users in areas with unstable or limited connectivity.

• Keeps civil time aligned with Earth's rotation
  Leap seconds keep UTC within 0.9 seconds of UT1, which is based on Earth's actual rotation. Clock time therefore stays tied to the position of the Sun and does not drift away from the solar day.
• Supports astronomy and celestial navigation
  Telescope pointing, satellite tracking and some legacy navigation systems assume UTC is close to UT1. Leap seconds avoid the need for separate corrections in those systems.
• Small, frequent adjustments instead of big jumps
  Adding single seconds when needed avoids a much larger correction later, such as a leap minute or leap hour, which would be more disruptive and harder to explain to the public.
• Internationally standardized process
  The IERS decides on leap seconds and announces them about six months ahead. This gives a single authoritative, globally coordinated mechanism that timekeeping systems can follow.

Possible disadvantages

• Causes software and infrastructure failures
  A 23:59:60 timestamp breaks assumptions in many systems, such as monotonic time and 60-second minutes. Past leap seconds have caused crashes, hangs and outages in operating systems, databases and cloud services.
• Unpredictable schedule
  Earth's rotation speed varies irregularly, so leap seconds cannot be predicted far in advance. Systems that need long-term time calculations cannot know future UTC offsets, so they need frequent updates.
• Inconsistent handling across systems
  Some systems step the clock, some repeat a second, and others smear the extra second over hours, as Google and AWS do. These differences can leave clocks briefly disagreeing, which hurts distributed systems, logging and financial timestamping.
• Being phased out
  In 2022 the CGPM voted to stop using leap seconds by or before 2035. Anything built around them has an uncertain long-term future, and the planned replacement will let UTC drift from solar time.
• Website details unverified
  I can't access https://www.leapsecond.co, so these points describe leap seconds as a concept, not that site's specific product or service. Check the site directly for its features, pricing and quality.

• "Ask a senior developer anything" Twitter Space: Questions and answers

  The best resource I know of is Javascript.com for learning Javascript for the first time. It's made by Pluralsight which is a site that contains courses. - Source: dev.to / over 4 years ago

Tracking Leap Second since Oct 2026.