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UnixTimestamp Blog Overview

Browse all articles and tutorials in one overview.

Calendars from different countries displayed side by side, highlighting how date formats vary across the world.
Aug 17, 2026 · 5 min

Why Date Formats Differ by Country and How to Avoid Ambiguity

The same string of numbers can mean two totally different dates depending on where you are. Write 03/04/2024 in the Un… Read more

A glowing clock face merges with Earth's rotation, illustrating the precision behind every leap second ever added to timekeeping.
Aug 10, 2026 · 6 min

Every Leap Second Ever Added and Why They Exist

A leap second is a one-second adjustment added to Coordinated Universal Time (UTC) to keep our atomic clocks in sync w… Read more

A torn calendar page revealing the 10-day gap of the 1582 Gregorian calendar reform, set against a warm Renaissance-era backdrop.
Aug 03, 2026 · 5 min

Why the Gregorian Calendar Skipped 10 Days in 1582

In October 1582, the calendar jumped straight from Thursday the 4th to Friday the 15th, erasing 10 days that simply ne… Read more

A spreadsheet on a glowing monitor displays epoch time values converting to readable datetime formats in Excel.
Jul 29, 2026 · 6 min

Convert Epoch Time to Datetime in Excel: A Practical Guide for Timestamps

Excel stores dates as serial numbers counting from January 1, 1900, while Unix epoch time counts seconds from January … Read more

A glowing coin cell battery sits beside an open laptop, illustrating how computers keep time when powered off.
Jul 22, 2026 · 6 min

How Your Computer Keeps Time When Turned Off

Your computer keeps time when it's off thanks to a tiny chip called the real time clock (RTC), which runs on a small C… Read more

Conceptual illustration of cron job troubleshooting, with broken automation on one side and a successful scheduled workflow on the other, highlighting logs, syntax, permissions, and environment issues.
Jul 15, 2026 · 6 min

Why Your Cron Job Is Not Running (And How to Fix It)

If your cron job is not running, the cause is almost always one of five things: cron uses a stripped-down environment … Read more

Conceptual illustration comparing International Atomic Time and Coordinated Universal Time, shown as two branching time paths with clocks, gears, and a globe.
Jul 08, 2026 · 5 min

TAI vs UTC: Why Atomic Time and Coordinated Time Diverge

TAI (International Atomic Time) and UTC (Coordinated Universal Time) are both built from the same super-precise atomic… Read more

Glowing abstract data streams arranged in ordered sequences, illustrating the concept of sortable IDs like ULID versus UUID.
Jun 24, 2026 · 6 min

ULID vs UUID: When Sortable IDs Actually Matter

The short answer: pick ULID when you need IDs that sort by creation time and stay readable, and pick UUID when you nee… Read more

Timeline diagram showing negative and positive values relative to a central reference point
May 12, 2026 · 7 min

Working with Negative Unix Timestamps: Dates Before 1970

A negative unix timestamp is simply a timestamp with a value below zero, representing a date and time that occurred be… Read more

Linux terminal converting a Unix timestamp to a readable date using the date command
May 01, 2026 · 7 min

How to Convert a Unix Timestamp to a Date in Linux: date, awk, and Bash Scripts

Converting a Linux timestamp to a date is something you'll do constantly as a developer or sysadmin, and Linux gives y… Read more

NTP time synchronization diagram showing interconnected time servers and clocks across a global network
Apr 22, 2026 · 9 min

What Is NTP Time Synchronization and How Does It Keep Clocks Accurate?

NTP time synchronization is the process by which computers, servers, and network devices automatically set and maintai… Read more

Modern illustration of glowing digital tokens and clock mechanisms representing JWT authentication timestamps and token expiration concepts.
Apr 14, 2026 · 8 min

JWT Expiration and Issued-At Claims: How Unix Timestamps Power Token Auth

Every time a user logs into a SaaS application, an auth token is generated and handed to their browser or mobile app. … Read more