Unix Epoch Lab

Analyze time as a numerical constant. Convert the Unix epoch seconds into human dates and explore their hexadecimal and binary serialized forms.

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The Universal Clock

Unix time (also known as Epoch time or Posix time) is a system for describing a point in time. It is the number of seconds that have elapsed since the Unix Epoch, which is 00:00:00 UTC on January 1, 1970.

Unlike standard calendar dates, Unix time is a monotonically increasing integer. This makes it exceptionally efficient for database indexing, sorting events, and calculating time differences in systems programming.

The Y2038 Threshold

Many legacy systems store Unix time as a signed 32-bit integer. The maximum value for such an integer is 2,147,483,647—a timestamp that corresponds to January 19, 2038.

When this limit is reached, systems will "overflow," causing the date to wrap around to 1901. Modern 64-bit systems are immune, as their capacity extends far beyond the lifetime of our solar system.

Developer Cheat Sheet

// JavaScript
Math.floor(Date.now() / 1000);
// Python
import time
int(time.time())
// SQL (MySQL)
SELECT UNIX_TIMESTAMP();
// Go
time.Now().Unix()
// PHP
time();
// Bash
date +%s

Milestones in Unix Time

0
Unix Epoch Begin
1,000,000,000
Sept 9, 2001
1,640,995,200
2022 New Year
2,147,483,647
Y2038 Deadline